Sometimes Aveva prompt forms or errors can get located off monitor. For example when invoking at@, thePoint Construction Option form opens but I can't see it. As workaround and having to go the Task Manager route, I temporarily change the Monitor display resolution within Display settings to say 1600 x1200. This prompts all the forms on that monitor to reposition themselves, allowing you to grab and then in this example..Cancel the form.
you can get rid of prompts by adding a line in your PML or macro as below. First and last line of your code.
PROMPT DISMISS