After going thru the Control Center Program Blueprint creation/configuration wizard, a very generic "Error! Please refresh and try again" error box popped up when hitting 'save'.
Needless to say, refreshing did not resolve the problem. More to the point, there were no details given in the error message to even begin to determine what could be wrong.
After many failed attempts and even recreating the Control Center Program anew, it turns out that the culprit was editing the config sheet directly to specify new program 'Lead' rather than going thru the Control Center UI. Learned the lesson the hard way that config sheet should not be edited directly under any circumstance.
Nevertheless, error messages need to be more specific and/or provide more detailed trace to more quickly diagnose and rectify. (Ideally, the process should be less brittle, but reality is that errors are going to happen, so the system should be more informative when they do.)