Finding and Reading Game Logs
Game logs are the primary diagnostic tool for troubleshooting Unturned™ mods. Every asset load failure, validation error, and runtime exception is recorded in the game's log files. Knowing where to find these logs, how to read them, and how to filter them for relevant information is an essential skill for any mod author or server operator. The game produces two main log files: Client.log (for client-side issues) and Server.log (for server-side issues). Additional logs are produced when specific diagnostic flags are enabled.
57 Studios™ has documented and validated the complete game log system. This reference covers the log file locations for Windows, Linux, and macOS installations, the structure of log entries, the patterns that indicate common mod issues, the log level configuration that controls verbosity, and the techniques for filtering logs to find specific asset errors quickly.
Documentation source: This article references the official Smartly Dressed Games modding documentation for the Asset Validation chapter, combined with the 57 Studios cohort's empirical analysis of log file patterns across common modding scenarios. Log file locations are based on the standard Steam installation directory structure.
Who this article is for
This guide is written for Unturned™ mod authors and server operators who need to diagnose issues by reading game log files. If you are new to modding, start with Project Folder Structure and GUIDs before returning here.
What you will learn
- Where the Client.log and Server.log files are located on each platform
- How to open and read log files with a text editor
- The structure of a log entry (timestamp, severity, message)
- The common error patterns that indicate mod-related issues
- How to filter logs for specific asset errors
- How to enable additional logging with command-line flags
Log file locations
The game stores log files in the Logs/ subdirectory of the Unturned installation directory. The default installation path on each platform is:
| Platform | Default installation path | Log file location |
|---|---|---|
| Windows (Steam) | C:\Program Files (x86)\Steam\steamapps\common\Unturned | <InstallDir>\Logs\Client.log |
| Windows (Steam) | Same as above | <InstallDir>\Logs\Server.log |
| Linux | ~/.steam/steam/steamapps/common/Unturned | <InstallDir>/Logs/Client.log |
| macOS | ~/Library/Application Support/Steam/steamapps/common/Unturned | <InstallDir>/Logs/Client.log |
The Client.log file records events from the client-side game process. The Server.log file records events from the dedicated server process. Both files use the same format and can be analyzed with the same techniques.
Log file structure
Each log entry follows a standard format with a timestamp, severity level, and message.
2026-07-26 14:30:00 - [Info] - Loading asset bundle core.masterbundle
2026-07-26 14:30:01 - [Warning] - Failed to find asset with GUID a1b2c3d4e5f64a7b8c9d0e1f2a3b4c5d
2026-07-26 14:30:02 - [Error] - Could not find master bundle CustomWeapons.masterbundle| Component | Format | Example | Meaning |
|---|---|---|---|
| Timestamp | YYYY-MM-DD HH:MM:SS | 2026-07-26 14:30:00 | The date and time of the event |
| Severity | [Severity] | [Error] | The severity level of the event |
| Message | Free text | Could not find master bundle... | The event description |
Severity levels
| Level | Meaning | Action required |
|---|---|---|
[Info] | Informational message | No action needed |
[Warning] | Non-critical issue; asset may have degraded functionality | Review and fix if possible |
[Error] | Critical issue; asset or feature failed to load | Investigate and fix |
[Exception] | Unhandled exception in the game code | Likely indicates a mod compatibility issue |
Common error patterns
The following table maps log entry patterns to their most likely causes and resolutions.
| Log pattern | Likely cause | Resolution |
|---|---|---|
Failed to find asset with GUID | A GUID reference could not be resolved | Verify the referenced asset is loaded |
Could not find master bundle | A master bundle file is missing | Copy the bundle file to the correct directory |
Parser error at line | A .dat file has invalid syntax | Fix the syntax error at the reported line |
duplicate GUID | Two assets share the same GUID | Generate a new GUID for one of the assets |
Mesh not readable | A mesh is missing the CPU Readable flag | Enable Read/Write in Unity import settings |
Missing localization file | No English.dat in the asset folder | Create English.dat in the asset folder |
Hash mismatch | Asset bundle version mismatch | Rebuild the bundle or update the version |
Could not find type | Asset type is not recognized | Verify the Type field in the .dat file |
Filtering logs for asset errors
When diagnosing a specific asset issue, filtering the log file for relevant entries is more efficient than reading the entire file.
Filtering by severity
Search for [Error] to find all critical issues. Search for [Warning] to find non-critical issues that may still affect functionality.
Filtering by GUID
If an asset has a known GUID, search for that GUID string in the log file. The search returns all entries that reference that specific asset.
Filtering by asset name
If an asset has a known name (the Name field from the .dat file), search for that name in the log file. Note that the log may reference the internal name rather than the display name.
Log level configuration
The default log level includes Info, Warning, and Error messages. Additional detail can be enabled through command-line flags.
| Flag | Additional logging | Use case |
|---|---|---|
-ValidateAssets | Comprehensive asset validation results | Before publishing a mod |
-LogLevelBatchingTextureAtlasExclusions | Atlas exclusion reasons | Optimizing level batching |
-ValidateLevelBatchingUVs | UV validation results | Verifying atlas compatibility |
-DisableCullingVolumes | No additional logging (disables feature) | Performance comparison |
The 57 Studios cohort recommendation is to always run with -ValidateAssets when diagnosing mod issues. The additional logging provides detailed information about every asset validation check.
FAQ
How do I open a log file?
Log files are plain text files that can be opened with any text editor. Notepad++ and VS Code are recommended for their search and filtering capabilities.
Can I delete log files?
Yes. Log files can be deleted safely. The game creates a new log file the next time it starts. Deleting old logs is recommended before diagnosing a fresh issue so that the new log file contains only entries from the current session.
Why is my log file empty?
An empty log file may indicate that the game started but did not reach the logging initialization stage. This can happen if the game crashes before the logging system is initialized. Check the Windows Event Viewer (on Windows) or system logs (on Linux) for crash information.
Do log files contain personal information?
Log files contain the file paths of loaded mods, which may reveal the Steam username used in the installation path. Log files do not contain passwords, credit card information, or other sensitive data. Server operators should review the log for any mod file paths that could reveal server directory structure before sharing logs publicly.
How often are log files written to?
Log entries are written in real time as events occur. The log file is continuously updated during the game session.
Log file analysis workflow
The following step-by-step workflow is recommended for analyzing log files during mod troubleshooting.
Step 1: Clear old logs
Delete the existing Client.log or Server.log file before starting a new diagnostic session. This ensures that the new log file contains only entries from the current session.
Step 2: Enable validation logging
Add -ValidateAssets to the game's launch options. This enables the comprehensive validation checks and logs the results.
Step 3: Reproduce the issue
Launch the game and perform the actions that trigger the issue. This could be loading a map, spawning an item, or connecting to a server.
Step 4: Capture the log
After the issue is reproduced, close the game and open the log file in a text editor. The log file contains the full session record.
Step 5: Filter for errors
Search for [Error] to find all critical issues. Review each error entry and note the associated GUID or file path.
Step 6: Filter for warnings
Search for [Warning] to find non-critical issues. Review each warning for relevant information about the issue.
Step 7: Trace the root cause
Starting from the first [Error] entry, trace the chain of dependent failures. The first error is typically the root cause.
Common log entry patterns for mod issues
| Log entry | Typical mod issue | Priority |
|---|---|---|
Failed to find asset with GUID X | Missing asset reference | High |
Could not find master bundle X | Missing bundle file | Critical |
Parser error at line X | Invalid .dat syntax | High |
duplicate GUID | GUID conflict | Critical |
Missing localization file for X | Missing English.dat | Low |
Asset X has duplicate GUID | Same GUID used twice | Critical |
Mesh X not readable | Navmesh won't bake | Medium |
Could not find type X | Invalid or unsupported asset type | High |
Log file management for server operators
Server operators should implement a log file rotation policy to manage disk space and maintain diagnostic history.
| Server size | Log retention | Rotation frequency | Notes |
|---|---|---|---|
| Small (1-10 players) | 30 days | Monthly | Keep logs for 1 month |
| Medium (10-50 players) | 14 days | Bi-weekly | Keep logs for 2 weeks |
| Large (50+ players) | 7 days | Weekly | Keep logs for 1 week |
Best practices
- Check the log file immediately after encountering any mod issue
- Clear old log files before starting a diagnostic session
- Use text editor search functionality to find relevant entries
- Run with
-ValidateAssetsduring diagnostic sessions - Save a copy of the log file before clearing it for reference
- Search for
[Error]first, then[Warning], then review Info entries
Appendix A: Quick-reference log analysis card
| To find | Search for | Example match |
|---|---|---|
| All errors | [Error] | [Error] Could not find master bundle... |
| All warnings | [Warning] | [Warning] Failed to find asset with GUID... |
| Missing asset | Failed to find asset | Failed to find asset with GUID a1b2c3d4... |
| Missing bundle | Could not find master bundle | Could not find master bundle Weapons.masterbundle |
| Syntax error | Parser error | Parser error at line 42: Unclosed dictionary |
| GUID conflict | duplicate GUID | Asset CustomRifle has duplicate GUID... |
Appendix B: Log file comparison between client and server
The following table compares the log file content between the client and server for the same event.
| Event | Client.log entry | Server.log entry |
|---|---|---|
| Asset load failure | [Warning] Failed to find asset with GUID X | [Warning] Failed to find asset with GUID X |
| Master bundle missing | [Error] Could not find master bundle X | [Error] Could not find master bundle X |
| Parser error | [Parser error] ... line Y | [Parser error] ... line Y |
| GUID conflict | [Error] Asset X has duplicate GUID | (not shown; GUID validation is client-side) |
| Invalid item reference | [Warning] Unknown item type for ID Z | [Warning] Unknown item type for ID Z |
Appendix C: Log file entry severity summary
| Severity | Meaning | Color in log | Priority |
|---|---|---|---|
[Info] | Normal operational message | None | None |
[Warning] | Non-critical issue detected | Yellow | Low |
[Error] | Critical issue; asset or feature failed | Red | High |
[Exception] | Unhandled exception | Red (bold) | Critical |
Appendix D: Log file FAQ for server operators
How do I share a log file for troubleshooting?
Share the log file through a pastebin service or by copying the relevant sections into a support ticket. Do not paste the entire log file into a chat message.
How large can a log file get?
Server log files can grow to hundreds of megabytes on busy servers. Implement the rotation schedule recommended in this article to manage file sizes.
Can I read a log file while the game is running?
Yes. The log file is written to disk in real time. Opening it in a text editor while the game is running is safe, but the file may be locked on some operating systems.
Appendix E: Complete log entry reference table
The following table documents every common log entry pattern, its severity, meaning, and recommended action.
| Log entry | Severity | Meaning | Action |
|---|---|---|---|
[Info] Loading asset bundle X | Info | Normal loading of an asset bundle | No action |
[Info] Asset X loaded successfully | Info | Asset loaded correctly | No action |
[Warning] Failed to find asset with GUID X | Warning | Missing GUID reference | Find and add the referenced asset |
[Warning] Mesh X is readable | Warning | Readable flag unnecessarily enabled | Disable Read/Write in Unity |
[Warning] Texture X is readable | Warning | Readable flag unnecessarily enabled | Disable Read/Write in Unity |
[Warning] High vertex count on mesh X | Warning | Mesh has too many vertices | Optimize mesh |
[Warning] Missing localization file | Warning | No English.dat present | Create English.dat |
[Error] Could not find master bundle X | Error | Master bundle file missing | Copy bundle to correct directory |
[Error] Parser error at line X | Error | Invalid .dat syntax | Fix syntax at reported line |
[Error] Asset X has duplicate GUID | Error | Two assets share the same GUID | Generate new GUID |
[Error] Missing mesh on renderer X | Error | No mesh assigned to Mesh Filter | Assign mesh in Unity |
[Error] Missing material on renderer X | Error | No material assigned | Assign material in Unity |
Appendix F: Log file command-line flags reference
| Flag | Purpose | Log output |
|---|---|---|
-ValidateAssets | Enable comprehensive validation | Detailed asset validation results |
-LogLevelBatchingTextureAtlasExclusions | Log atlas exclusion reasons | Atlas exclusion messages |
-ValidateLevelBatchingUVs | Validate UV coordinates | UV out-of-bounds messages |
-PreviewLevelBatchingTextureAtlas | Visualize atlas inclusion | No log output (visual mode) |
-PreviewLevelBatchingUniqueMaterials | Visualize unique materials | No log output (visual mode) |
-DisableCullingVolumes | Disable culling volumes | No log output (feature toggle) |
Appendix G: Log-based diagnostic workflow for common mod issues
The following workflows use log entry analysis to diagnose specific mod issues.
Issue: Item does not appear in-game
- Search Client.log for
Failed to find asset. If found, note the GUID and find which asset references it. - Search for
duplicate GUID. If found, generate a new GUID for one of the conflicting assets. - Search for
Parser error. If found, fix the syntax error at the reported line. - Search for
Missing localization file. If found, create English.dat for the affected asset.
Issue: Item appears but is invisible when equipped
- Search Client.log for
Could not find master bundle. If found, add the missing bundle file. - Search for
prefab not found. If found, verify the prefab name in the .dat file matches the bundle content. - Search for
Missing mesh. If found, assign a mesh in Unity and re-export.
Issue: Server shows asset mismatch errors
- Search Server.log for
hash mismatch. Note which asset is mismatched. - Compare the Asset_Bundle_Version on the client and server.
- Update the client or server to use the same bundle version.
Appendix H: Log file entry count by severity (typical session)
The table below shows the typical number of log entries by severity for a normal game session versus a session with mod issues.
| Severity | Normal session | Problematic session | Notes |
|---|---|---|---|
| Info | 200-500 | 200-500 | Normal loading activity |
| Warning | 0-5 | 10-100+ | Increase indicates mod issues |
| Error | 0 | 1-20+ | Any error indicates a problem |
| Exception | 0 | 0-3 | Rare; indicates serious issue |
Appendix I: Full log analysis workflow table
| Step | Action | Tool | Expected outcome |
|---|---|---|---|
| 1 | Clear old logs | File Explorer delete | Empty log directory |
| 2 | Enable validation | Add -ValidateAssets to launch options | Comprehensive validation logging |
| 3 | Launch game | Steam client | Game loads with mods |
| 4 | Reproduce issue | In-game actions | Issue triggers log entries |
| 5 | Close game | Exit game | Log file finalized |
| 6 | Open log file | Text editor (Notepad++) | View full session log |
| 7 | Filter for errors | Search for [Error] | All critical issues listed |
| 8 | Filter for warnings | Search for [Warning] | All non-critical issues listed |
| 9 | Trace root cause | Read first error entry | Root cause identified |
| 10 | Fix issue | Edit mod files | Issue resolved |
| 11 | Retest | Repeat steps 2-5 | Confirmation that issue is fixed |
| 12 | Verify clean log | Repeat steps 6-8 | No remaining errors related to the fix |
Appendix J: Log file analysis for common server issues
The following table maps server-side log patterns to common server issues.
| Server log pattern | Server issue | Resolution |
|---|---|---|
[Error] Could not find master bundle X | Missing mod bundle file | Add bundle to server Bundles/ directory |
[Warning] Failed to find asset with GUID X | Missing asset reference | Add the referenced mod |
[Error] duplicate GUID | Two mods conflict | Generate new GUID for one mod |
[Warning] Hash mismatch for asset X | Client-server version mismatch | Update client or server to match |
[Error] Parser error at line X | Corrupted .dat file on server | Re-upload the mod files |
[Warning] Missing localization file | Missing English.dat | Add English.dat to the asset folder |
Appendix K: Common server log patterns reference
| Server log pattern | Meaning | Severity | Recommended action |
|---|---|---|---|
[Info] Server started on port 27015 | Server started normally | Info | None |
[Info] Loading workshop file X | Workshop mod loading | Info | None |
[Warning] Workshop file X not found | Workshop mod missing | Warning | Re-check server Workshop config |
[Error] Could not bind to port 27015 | Port already in use | Error | Change server port |
[Warning] Player X timed out | Player disconnected | Warning | Check network connection |
[Error] Asset validation failed for X | Asset load failure | Error | Fix the referenced asset |
[Warning] Stack trace logged | Exception occurred | Warning | Check preceding log entries |
[Info] Server shutting down | Normal shutdown | Info | None |
Appendix L: Log file backup and rotation script
The following script demonstrates log file rotation for server operators.
powershell
$logDir = "C:\Unturned\Servers\MyServer\Logs"
$backupDir = "C:\Unturned\Servers\MyServer\Logs\Backup"
$date = Get-Date -Format "yyyy-MM-dd"
Move-Item "$logDir\*.log" "$backupDir\$date" -ErrorAction SilentlyContinueAppendix M: Log file analysis quick-reference card
| Situation | Log to check | Search for | Expected finding |
|---|---|---|---|
| Mod not loading | Client.log | [Error] | Asset load failure details |
| Item invisible | Client.log | Failed to find asset | Missing GUID reference |
| Server not showing | Server.log | [Error] | Port binding or startup issue |
| Pink textures | Client.log | Missing material | Material not assigned |
| Hash error | Client.log | Hash mismatch | Version mismatch details |
| Random crashes | Both | [Exception] | Unexpected error details |
| Performance issue | Client.log | High vertex or High material | Resource usage warnings |
Appendix N: Additional resources for log analysis
| Resource | Description | URL |
|---|---|---|
| SDG modding documentation | Official documentation for asset validation and logging | https://docs.smartlydressedgames.com/en/stable/ |
| Unity documentation | Unity log file format reference | https://docs.unity3d.com/Manual/LogFiles.html |
| 57 Studios KB | Troubleshooting section for log-related issues | https://docs.57studios.net/troubleshooting/ |
Appendix O: Log file location quick-reference by platform
| Platform | Client.log | Server.log | Notes |
|---|---|---|---|
| Windows (default) | C:\Program Files\...\Unturned\Logs\Client.log | C:\Program Files\...\Unturned\Logs\Server.log | Default Steam install |
| Windows (custom) | <InstallDir>\Logs\Client.log | <InstallDir>\Logs\Server.log | Custom install location |
| Linux | ~/.steam/steam/.../Unturned/Logs/Client.log | ~/.steam/steam/.../Unturned/Logs/Server.log | Default Steam install |
| macOS | ~/Library/.../Unturned/Logs/Client.log | (no server on macOS) | Default Steam install |
Appendix P: Log file size limits and management
| Server type | Typical daily log size | Max recommended size | Rotation frequency |
|---|---|---|---|
| Small (1-10 players) | 1-5 MB | 100 MB | Monthly |
| Medium (10-50 players) | 5-20 MB | 250 MB | Bi-weekly |
| Large (50+ players) | 20-100 MB | 500 MB | Weekly |
| Large with validation | 100-500 MB | 1 GB | Daily |
Log files larger than the recommended maximum should be rotated immediately. The game appends to the log file without truncation; old entries accumulate indefinitely.
Appendix Q: Log file analysis for common server startup scenarios
| Scenario | Expected first log entry | Expected last log entry | Total entries |
|---|---|---|---|
| Clean startup | [Info] Starting Unturned... | [Info] Server ready | 200-500 |
| Missing mod | [Info] Starting Unturned... | [Error] Could not find master bundle X | 50-100 |
| Mod conflict | [Info] Starting Unturned... | [Error] Asset X has duplicate GUID | 100-300 |
| Port conflict | [Info] Starting Unturned... | [Error] Could not bind to port | 10-30 |
| Corrupted save | [Info] Starting Unturned... | [Warning] Failed to load save data | 50-100 |
Appendix R: Log file reading best practices summary
- Always clear old logs before a diagnostic session
- Always enable -ValidateAssets for comprehensive logging
- Search for
[Error]first, then[Warning], then[Info] - The first
[Error]is usually the root cause - Save log files before clearing them for future reference
- Check both Client.log and Server.log when diagnosing server issues
- Filter by GUID when tracing specific asset references
Appendix S: Log file analysis for specific mod issues
| Mod issue | Log pattern | Additional context | Action |
|---|---|---|---|
| Weapon not spawning | Failed to find asset | GUID in log | Add referenced asset |
| Vehicle invisible | Could not find master bundle | Bundle name in log | Copy bundle to directory |
| Map fails to load | Asset validation failed | Validation details | Fix reported issues |
| Mod conflicts | duplicate GUID | GUID in log | Generate new GUID |
| Spawn table empty | (no log entry) | N/A | Check spawn table weights |
| Crash on join | Hash mismatch | Asset name | Synchronize versions |
Appendix T: External links for log analysis tools
| Tool | Purpose | Platform |
|---|---|---|
| Notepad++ | Text editor with search and syntax highlighting | Windows |
| Visual Studio Code | Text editor with search, filtering, and git integration | Windows, Linux, macOS |
| grep (command line) | Fast pattern search in log files | Linux, macOS, Windows (Git Bash) |
| Select-String (PowerShell) | Pattern search in log files | Windows |
| Log file analyzer | Custom tool for Unturned log analysis | Community-created |
Appendix U: External references
The 57 Studios documentation team maintains this guide to help mod authors and server operators diagnose issues through log file analysis. Effective log analysis is a foundational skill for any mod developer who publishes server-side content.
| External reference | Description | URL |
|---|---|---|
| SDG Asset Validation | Official validation documentation | https://docs.smartlydressedgames.com/en/stable/ |
| Unity Log Files | Unity documentation on log files | https://docs.unity3d.com/Manual/LogFiles.html |
| 57 Studios KB | Troubleshooting section index | https://docs.57studios.net/troubleshooting/ |
Appendix V: External references Understanding log files is an essential skill for anyone who maintains modded Unturned servers.
- Smartly Dressed Games official modding documentation - the authoritative reference for asset validation and logging.
- Asset Load Failure Reference - covers the load failures that appear in log entries.
- Asset Validation Error Reference - the next article; covers validation error severity classification.
- Data File Troubleshooting - covers
.datfile errors that appear in logs as parser errors.
Regular log file analysis is an essential practice for maintaining healthy modded Unturned servers and diagnosing mod issues quickly.
Authoring checklist
- [ ] Know the log file location for the target platform
- [ ] Can identify
[Error],[Warning], and[Info]severity levels - [ ] Can filter logs by GUID, asset name, or error type
- [ ] Can run the game with
-ValidateAssetsfor detailed logging - [ ] Clear old logs before starting a diagnostic session
The 57 Studios documentation team recommends that all server operators implement a log review routine as part of their server maintenance schedule.
The 57 Studios documentation team maintains this guide as part of the comprehensive modding knowledge base. Feedback and corrections from the community are welcomed through the standard documentation contribution process.
Document history
| Version | Date | Author | Notes |
|---|---|---|---|
| 1.0 | 2026-07-26 | 57 Studios | Initial publication. Complete guide to finding and reading game logs with file locations, entry structure, error patterns, and filtering techniques. |
This document is maintained by the 57 Studios documentation team.
The 57 Studios documentation team maintains this guide as a living document. Feedback and corrections from the community are welcomed through the standard documentation contribution process.
The 57 Studios documentation team maintains this guide as a living reference for log analysis techniques. Regular log review is essential for maintaining server health and diagnosing mod issues quickly.
Cross-references
- ID Conflict Resolution - the previous article in the troubleshooting section.
- Asset Validation Error Reference - the next article; covers validation error severity classification.
- Asset Load Failure Reference - covers the load failures that produce log entries.
- Data File Troubleshooting - covers
.datfile errors that appear in logs. - Smartly Dressed Games modding documentation - official reference.
- Unturned on Steam - game page and community hub. The official source for game update information that may affect logging behavior. Check the changelog regularly for logging system changes.
- Server Connection Timeout - covers server connectivity issues that may be diagnosed through log analysis.