Join with the launcher
- Download the FoundryMTR Launcher from the downloads page.
- Install and open it.
- Sign in with Microsoft.
- Click Play.
- The launcher installs the modpack and connects you to the server.
How to play
Join FoundryMTR
The launcher installs everything and connects you in a few clicks.
Manual connection (supported)
mc.foundrymtr.com
Troubleshooting
If something goes wrong
The launcher won’t open
Make sure you downloaded it from files.foundrymtr.com. On Windows, allow it through SmartScreen (More info → Run anyway). On macOS, see Gatekeeper below. If it still fails, check the Status page for known issues.
Microsoft login failed
Login happens directly with Microsoft inside the launcher. Try signing out and back in, confirm your Microsoft account owns Minecraft Java Edition, and check your internet connection. The website never handles your password.
A mod download failed
The launcher verifies every file by size and checksum and will re-download corrupt files. Re-run the launcher; if a specific file keeps failing, the Status page will note any distribution outage.
Minecraft says mods are incompatible
Let the launcher manage the modpack — do not add your own mods to the FoundryMTR profile. The required set, Fabric loader, and Minecraft version are pinned to match the server.
Windows SmartScreen warning
The launcher is open-source and currently unsigned, so SmartScreen may warn on first run. Choose “More info” → “Run anyway”. Verify the download’s checksum on the Downloads page if unsure.
macOS Gatekeeper warning
The build is not yet notarized. Right-click the app → Open, then confirm. Only do this for files downloaded from files.foundrymtr.com.
Server connection failed
Confirm the address is mc.foundrymtr.com on Minecraft 1.21.4 with the FoundryMTR modpack loaded. If the server is down for maintenance it will be noted on the Status page.