Crystal XI is old and has been out of support for several years. Are you on the original version of XI (version 11.0.x) or XI r2 (version 11.5.x)? If you're on the original version you should upgrade to the last SP that was available. You can get to it through here:
Where did all the Crystal Reports XI r1 and r2 fixes go?
If that doesn't allow you to connect, I suspect you'll need to upgrade to the latest version of Crystal. You can get a 30-day free trial from here
Crystal 2013 trial download
-Dell