Welcome to the Unreal Forums! Are you getting an error code with this? (Something such as ExitCode=6?) If that is the case, you may be able to reset your game Icon in your project back to default and fix it. If that’s not it, can you provide the full error that you’re receiving? I hope this helps!
To add on just a bit more to what @FrostyJas explained, do you have Editor symbols for debugging installed into your version of UE? Can you share any logs you have after building and getting that error?
Any additional specifics you can provide may go a long way in solving your problem!
I have the same problem, and I downloaded “Editor symbols for debugging” but it still gives me the same error (PackagingResults: Error: Unknown Error).