I set it to modal, and it works. Perhaps the setting is ignored? Anyway, after setting up the READ EVENTS, it worked.
>TopLevel form cannot be modal
>
>>OK, thanks to you both. It turns out I also had to add a missing READ EVENTS: I thought that, if I had main form modal, that might not be necessary, but it didn't work.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)