Seagate External HDD keeps disconnecting

This mostly happens when playing games. No problems at all for most of the match, but then I hear the Windows dosconnect sound, and the game crashes. I don't even have to reconnect it, because it gets automatically reconnected.

A while ago I didn't have ANY problems with it, it worked perfectly, but now I can't even play one match before it disconnects. It has always been a problem, but now it's getting stronger. What can I do?