Fixing common problems

Most problems with passthrough mods come down to a handful of causes. Work through these before asking for help, and if you do ask, include what you found.

"Nothing happens"

The mod doesn't seem to load at all.

• Wrong game version. Most mods are locked to specific versions. Compare your game version with the project's requirements (the What you need box on its page).
• Not started through the loader. Skyrim must start via SKSE, Outer Wilds via its mod manager, and so on.
• Loader for the wrong version. Reinstall the loader build that matches your game.
• Missing dependency. Address Library, Fabric API and similar are easy to forget.

The hidden game never starts

Passthrough mods start the guest game (often Minecraft) in the background.

• It's waiting for you. Alt-Tab: there may be a launcher window asking you to sign in, or downloading files on first run.
• Java or the launcher is still downloading. The first start can take several minutes.
• It started, then quit. Check the guest game's log. For Minecraft that's the instance's logs/latest.log.
• Both games must run with the same rights. If one runs as administrator and the other doesn't, Windows can stop them from talking to each other. Run both normally.

It worked yesterday, broken today

• The game updated. Steam updates can break version-locked mods overnight. Check the project's page and releases for a fix, and look at the Works for me reports to see which versions others use.
• Prevent surprise updates: in Steam, Properties → Updates → Only update this game when I launch it, and launch through the mod's loader. Some games let you pick an older version under Properties → Betas.

Black screen, missing blocks, or the guest picture is in the wrong place

• Laptops with two graphics chips: both games must run on the same GPU, or they can't share pictures. In Windows Settings → System → Display → Graphics, set both games (and their launchers) to High performance.
• Overlays get in the way. Turn off the Discord, Steam, GeForce/AMD and MSI Afterburner/RivaTuner overlays while testing, especially with ReShade-based mods.
• Display mode. Some mods need windowed or borderless mode at a specific resolution. Check the README.

Antivirus removed a file

Code injection looks suspicious to antivirus tools. If the file came from the official release page, restore it from quarantine and add an exception for that one folder. Never disable your antivirus completely. See Staying safe.

Can't write files / "access denied"

Don't extract mods or rewrites into Program Files, or into a OneDrive-synced folder like Documents or Desktop if OneDrive is acting up. Use a plain folder such as C:\Games\ModName.

Too slow or stuttering

Two games at once is heavy. See Will my PC run it?.

Asking for help that gets answers

Post in the Help forum (or the project's GitHub issues) with:

1. The mod name and version (release tag).
2. Your game versions (all of them).
3. What you did, step by step, and what happened instead.
4. The log file. Most mods write one, and the README says where.
5. Your OS (Windows 10/11, Linux/Proton) and GPU.

When someone solves it, mark their reply as the answer so the next person finds it.