Well, first check the version they are on now, since it might already be 5.00b. In Crystal, go to File/Summary Info and check the Keywords field. If it says 5.00, you're pretty much guaranteed to be screwed. If it is already 5.00b, all is well.
One other thing - if you have a report on 5.00 and it won't convert automatically to 5.00b for whatever stupid reason (mascrw doesn't seem to work as well as it used to), you can just pull it up and change the version manually and it should run fine. I've even done that between 5.00 and 5.10 (2014). Also you can manually do that before adding a new custom report to a menu and it won't do the conversion thing. AND you don't have to have ""Converted to"".... you just have to have the version, all by itself, if you're in a hurry.