It's in a menu bar's Click method: =DOFORM('app_frm'). This is one of several new forms that I created and placed in a new *.vcx file. I've traced the SET('ClassLib') and the new *.vcx shows in the path, but it still works in dev but not under production. Searching back thru the threads, this type of problem has happened to several others, but not exactly in this fashion.

I just tried this - in the project manager I copied each new form by dragging from the new *.vcx into a previously-existing *.vcx and then removed the new *.vcx from the project. Voila - everything works in both dev and production. If I create another new *.vcx and create a new form there - those new forms work in dev but crash in production. So, apparently my MM system has developed an aversion to creating new *.vcx libs. Is there by chance a maximum number of classlibs that can exist, or maybe a maximum length to the SET('Classlibs') string?