Windows OS and LC969 weirdness

[Paul Dupuis]

I have a weird problem and I am wondering if anyone has seen anything 
like it.

I have an desktop app, built in Livecode 9.6.9 and running under Windows 
10 and 11. The app has stacks/windows to display different types of 
content docText for text, docPDF for PDFs, docImage for images, docMedia 
for player based audio or video. Only 1 of these windows can be open at 
a time. If you try to call up information of another type, it closes the 
current content window and opens the appropriate stack to display the 
new type of information.

Here is the weirdness. On a single monitor system, I can switch between 
these content windows endlessly
On a 2 monitor system, if all the windows are on the primary monitor, I 
can switch between them endlessly
On a 2 monitor system, I can place any of the content windows EXCEPT the 
media player (docMedia) on either monitor and swithc between them endlessly
On a 2 monitor system, if I put the media player window on the secondary 
monitor and try to switch bring up another content windows (docText, 
docPDF, docImage) - whether on the primary or secondary monitor, I get 
frozen app and Windows spinning blue cursor (the app is non-responsive, 
like in an endless loop)

Now, the above is with a built standalone. If I run the app in the LC969 
IDE, I get the same behavior above if I just let things run.

If I enter the debugger, the code sequence is roughly:

a) if the new info to display is of a different type that the current;y 
displayed info, then
     test in a loop through the app's open windows to see if one of 
these content windows is open and then close stack <name> to close it
b) open the applicable window for the new information and display it

If I walk through, in the IDE debugger, every line single line by single 
line, it all works, including stepping through the stack 'closeStack' 
handler
If I tell the debugger to run through the code above, rather than step 
line by line, the freeze happens

But again, ONLY when the docMedia window (with a player object and a few 
fields and buttons) is on a secondary monitor.

Has anybody seen any weirdness like this? The fact I can debug through 
it line by line and it does not freeze means finding what may be 
triggering it seem very hard (to me at least).