The LaunchCondition table is empty. I'm not sure how to do a full text search, clicking on the Direct Editor, I did Edit->Find for "setup cannot continue" (without the parentheses), there were no matches (I did continue the search at the beginning as prompted). I did it for "cannot continue" and found several matches, none that had the whole message.
I created all the custom actions, none of which have a message like the offending one.
[MyProgram] is PI_Dats, just an executable name.
I don't know how to disable prerequisites, I have never knowingly edited the prerequisite table. There are no Conditions, no Files to Include, no Application to Run,
no Dependencies. Under Behavior I have checked "The prerequisite requires administrative privileges". Below the choice is "Ask whether to continue the setup."
My boss says that if this problem is too tough, not to worry about it, so it is no longer a high priority. I would still be interested in fixing this, but if you're no longer inclined to pursue this, please don't. Thanks again for your help so far.