Fellowship: Fix “A Product Installation Has Been Detected” Launch Error

Published October 18, 2025

Getting the “A product installation has been detected” error and nothing else shows up? Try ArcRepair.exe, and if you’re on Steam, delete the Arc folder to get in.

If you launch the game and it throws that “A product installation has been detected. Please remove the existing installation before continuing.” message, you’re not alone. It’s annoying, but there are a couple of quick moves that have worked for players.

What’s happening

You hit launch, the error pops, and the game doesn’t open. Reinstalling might help, but there are faster fixes to try first.

Quick fixes that actually helped

Run the repair tool: open C:\Program Files (x86)\Arc\ and launch ArcRepair.exe.
Steam users: if you still can’t log in after installing, delete the Arc folder in C:\Program Files (x86).
Reinstall as a fallback if the above doesn’t clear the block.

Step-by-step: Run ArcRepair

Go to C:\Program Files (x86)\Arc\
Double-click ArcRepair.exe
Let it finish, then try launching the game again

For Steam players: Remove Arc

Open C:\Program Files (x86)\
Delete the Arc folder
Relaunch via Steam and try logging in again

Last resort: Reinstall

If the repair and Arc folder cleanup didn’t do it, reinstall the game and try again. It’s not instant, but it can clear leftover files that trigger the error.

Hope this gets you past the error and into the game. If one step doesn’t work, try the next in the list.

#Fellowship