When I informed him that the new version solved the problem he responded with the following:
“The problem is the splash screen, however transient, which I gather is related to their script-blocking feature. The newer version of Montage is smarter about not being fooled by such distractions.”.

So I cannot say what he did in the program, but since he was unaware of this specific problem and sent me the newer version quickly after my message, I gather that he had “tightened up the code” in that area of the program independently of this issue.

Sorry that I cannot be more precise.