My RCTs stopped working!

My RCTs don't load anymore. The producer logos don't come up on RCT2, and in RCT3, I try to upload or start a sandbox, and it will start loading, and then the screen goes black. Can someone help me?

A little more information might be of some help. Exactly what kind of errors are you getting. And please keep the errors separate from each other, mixing RCT2 and RCT3 together doesn't work too well.