For me game is running. I have the newest update of Marvel Rivals Version 20250515. In the past it would not run with Proton Experimental and had to switch to Proton 10.0-1 (beta) (still do). Also had to add SteamDeck=1 %command%, to make it run again. It runs right now as I write.

Sometimes after a system update I need to restart, otherwise games don’t launch. So maybe do system update now and restart entire PC and operating system, if you didn’t already.

1. Don’t use the same password on Steam that you use from other services.
2. Use a long password, with random characters and numbers.
3. Use a password manager.
4. Do not click on links in emails, unless you are 100% sure its from Valve. Better yet, visit Steam in your browser or the Steam app and search for the page there directly. Do not login on random websites requiring you to login to Steam.
5. Do not click on links in chat from people you don’t know or added recently to your friends list.
6. Set your Steam profile to private, or enable it for friends only at best. Especially if you have lot of skins.
7. Ultimate weapon: Use official 2FA (2 factor authentication) with Steam app on your phone. Do not lose your phone, as you cannot login to Steam otherwise.

No security is perfect, but following these basic rules will help you to secure your account. And there shouldn’t be any need to reset the password often. If you feel better, reset it once per year or so. I don’t.