I have a big problem. All my Steam games I had on an external hard drive are gone. Can anyone

So again I would have to reinstall all my games and that would take a long time, because I have also installed many big games such. Arma3, Rainbow and others. That's why you would like to know if you can fix it. The Steam recognizes these games again. Still a little note, I have often taken my external hard drive with me somewhere and then plugged it back into my laptop and then Steam did also recognized immediately.

Try it out, if it works or not:

https://steamcommunity.com/...257695385/

Try to check the game files.