How to Report a Proton Compatibility Problem

If a game won’t launch or misbehaves under Proton, Valve’s compatibility layer for Windows games on Steam Deck and Linux, reporting it properly can get it fixed faster. This guide walks you through gathering the right logs, filing a clear report, and following up so the Proton team and community can actually use your information.

What You’ll Need

A Steam account with the game in your library (even if it’s refunded, you can still report).
The game installed on your Steam Deck or Linux PC.
Access to your Steam Library and Settings menus.
Optional but helpful: a GitHub account (for browsing existing issues) and a text editor for notes.

Step-by-Step

Reproduce the problem. Launch the game through Steam and trigger the issue. Note whether it happens on first launch, after a cutscene, when changing graphics settings, or during multiplayer. If the game crashes, let it crash completely—don’t force-quit unless it freezes.
Note your environment. Go to Steam > Settings > System (or Steam > About on desktop) and write down your Steam client version, Proton version (Steam > Settings > Compatibility), your operating system (SteamOS version or Linux distro), and your GPU/driver info (from Steam > Settings > System or your system info tool).
Try a different Proton version. Right-click the game in your library, select Properties > Compatibility, and try Proton Experimental, Proton 9.0, or Proton 8.0. Also try Proton Hotfix if available. Note which versions fail and which succeed (or fail differently). This helps narrow down regressions.
Enable logging. In the game’s Properties, under General, set Launch Options to include PROTON_LOG=1 %command% (or PROTON_LOG=1 for non-Steam games). This creates a log file. For Steam Deck, you may need to use Desktop Mode to find it.
Find the log. After running the game with logging enabled, the log is saved to ~/steam-.log on Linux, or /tmp/steam-.log on Steam Deck. You can also find it in the game’s pfx/drive_c/users/steamuser/Temp folder. Copy the log to a safe location.
Check for existing reports. Go to the Proton GitHub issue tracker (github.com/ValveSoftware/Proton/issues) and search for the game name or the specific error. If an issue already exists, add your log and system info as a comment instead of creating a duplicate.
Create a new issue (if needed). Click “New Issue” and choose the bug report template. Fill in the title with the game name and a short summary (e.g., “Game X crashes on launch with Proton 9.0”). In the body, include: your system info, Proton version, the exact steps to reproduce, the expected vs actual behavior, and any error messages you saw.
Attach the log. Drag and drop the log file into the issue, or paste a link to a pastebin service if the log is too large. Do not paste the entire log into the issue body—it makes it hard to read.
Submit and follow up. After submitting, watch the issue for questions. Developers or other users may ask for more details. Respond promptly with additional logs or tests if requested.

Common Mistakes

Not enabling logging. Without a log, developers can’t see what’s happening. Always include one.
Using the wrong Proton version. Reporting a bug that only happens on an old Proton version without mentioning it wastes time. Always test on the latest stable and Experimental.
Duplicate reports. Filing a new issue when one already exists splits the discussion. Search thoroughly first.
Vague descriptions. “Game crashes” is useless. Include the exact moment it crashes, any error codes, and what you were doing.
Forgetting system info. GPU, driver, and OS matter a lot. Include them even if you think they’re irrelevant.
Posting personal info. The log may contain your username or paths. Review it before sharing, and redact anything sensitive.

Tips

Use Proton Experimental for testing. It gets updates frequently and is the first place bugs are fixed.
Check ProtonDB. The community site protonDB.com often has workarounds and reports from other users. Mention in your issue if a workaround exists (like a specific launch option) but still doesn’t fix the core problem.
Keep logs short. If the log is huge, try to reproduce with a minimal session (launch, crash, exit). You can also use PROTON_LOG=1 and then trim the log to the relevant section if you know what to look for.
Be patient and polite. The Proton team is small and issues can take weeks. Bumping your issue after a month is okay, but don’t spam.
Test on Windows if possible. If the game works fine on Windows, that confirms it’s a Proton-specific issue. If it also fails on Windows, it’s a game bug and you should report to the game developer instead.

Troubleshooting

What if the log doesn’t appear? Make sure you used the exact launch option syntax. For Steam games, it’s PROTON_LOG=1 %command%. For non-Steam games added to Steam, it’s the same. If you’re on Steam Deck, switch to Desktop Mode and check /tmp or ~/.steam/steam/steamapps/shadercache.

What if the game doesn’t even launch with logging? Try running the game from the terminal to see console output. On Linux, you can run steam -applaunch and watch the output. On Steam Deck, use Desktop Mode and open a terminal.

What if the issue is already reported but closed? If it’s closed as “not a bug” or “works for us,” add a new comment with your fresh log and system info. If it’s closed as “duplicate,” just add to the original issue.

What if you can’t create a GitHub account? You can still report via the Steam forums or ProtonDB, but GitHub is the official channel. If you can’t, at least post on ProtonDB and link to any existing GitHub issue.

What if the game is not on Steam? Proton can run non-Steam games, but the Proton team primarily handles Steam games. For non-Steam, try Lutris or Bottles, and report to those projects instead.

Frequently Asked Questions

Q: Do I need to include the entire log? A: No, but include the relevant sections. If you’re unsure, include the whole log as a file attachment, not pasted.

Q: What if the game crashes on both Proton and Windows? A: Then it’s likely a game bug. Report it to the game developer, not Proton.

Q: How long does it take to get a response? A: It varies. Some issues get attention in days, others take months. Be patient and check back.

Q: Can I report a game that I don’t own? A: You can, but without being able to reproduce it, your report will be less helpful. It’s better to only report games you can test.

Q: What is Proton Experimental? A: It’s a beta branch of Proton that gets frequent updates. It’s the best place to test if a bug is already fixed.

Q: Should I report a game that works but has minor graphical glitches? A: Yes, those are valid bugs. Include screenshots or video if possible.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.

More cards in this drawer

The whole Numbers and Powers drawer →