Gee, is replying to yourself like talking to yourself?

Just wanted to let the world know that after two weeks I still haven't figured this out. Tried various things people suggested, but still get the "Invalid Property Value" error in the scenario I originally described. Hoping somebody will have some additional ideas. Unfortunately this error seems to be coming from Windows Forms rather than Excel, and there's no error number or other clue associated with it to give me a way of researching it further.

"LarryP" wrote:

Have a form in an Excel file. Have a Control on the form
("ControlX"), default value of which is "". When entering
ControlX, check is performed to ensure a prior control
contains an appropriate value. When exiting ControlX
(i.e., upon AfterUpdate), ControlX value is saved to a
global variable for later use. All this works fine during
the normal sequence of events.

However, if the user returns to ControlX and deletes the
value (as in "Oops, I made a mistake"), and then tries to
go to another control, he gets a "Invalid Property Value"
error message generated by Microsoft Forms (or so I infer
from the Blue Bar on the error message popup).

I've tried a couple of different error-trapping structures
to deal with the fact that something out there in the
background obviously doesn't like a null value in
ControlX, including one that set the value back to ""
instead of Null, but so far no luck, still get the
message. Anyone have any suggestions?