Inject failed

Timing & order

The single most common cause: the loader was launched after the game. The watcher is designed to attach to a fresh spawn — if Marvel Rivals was already at the main menu when you clicked Launch Nimbus, the inject window has already closed.

Fix:

1. Close Marvel Rivals.
2. Click Launch Nimbus in the loader.
3. Wait for the watcher state to say "Waiting for Marvel Rivals…".
4. Start the game.

Real-time AV blocking

Some AVs (Bitdefender, Norton, Avast at default sensitivity) will silently block a write to the game's Engine\Binaries\ThirdParty\Ogg\Win64\VS2015\ folder because "unsigned process modifying a game install" looks suspicious to them.

Fix: add an exception for your Nimbus folder in the AV. We don't recommend disabling AV entirely.

Wrong install path

If the loader auto-detection guessed your Marvel Rivals install incorrectly (most often when you have both a Steam and an EGS copy), it will write the payload to the wrong folder and the game won't pick it up.

Fix: in Loader → Settings → Game Path, set the explicit path to the folder containing MarvelRivals_Launcher.exe.

Run with --verbose

Run from a terminal:

Launch Nimbus.bat --verbose

The last 10 lines of the verbose log usually tell you exactly which step failed. Paste those into your support ticket.