Invalid disc copy: Not a game killer but annoying

[simlishlol]

So lately whenever I open up my game I get that "We can not verify that your disc is a valid copy" or whatever it says. It's not too bad, because it only happens once and when I open it again it doesn't come up, but considering it comes up every day I play, I'd like to see if I can fix it. I've had this happen before except it came up every time. Any suggestions? Thanks in advance!

-Simlish