>>>>Any ideas on what would cause the form close button to become disabled during normal data entry operation with a modeless form? The form seems to be otherwise fully functional, can change pages in pageframe, can select another form, can minimize the form, menu options are functional, etc.; just can't close it. Toolbar form close button is also disabled when that form is active. FWIW, some data entry on the page where this seems to occur is in a grid, but that remains fully functional as well.
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>>>Is it called from the Modal form?
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>>No, no modal forms involved at all.
>
>Another relevant thread is this message #1252093

I had seen that one as well. Again there aren't any modal forms involved and the _screen close button does work; i.e. will close the uncooperative form, along with everything else.