I have a winforms app (>75k lines of source code), I have just added some new functionality and a new form and I'm getting the 'can't create window handle' error but only when running inside VS. The app builds OK and when i run it as the executable it is using 597 handles, 94 GDI and 83 USER and the new form works just fine apart from my logic errors in it. So as far as I can tell; my app is well below the 10,000 limit where things start to break therefore the problem is in/with VS somewhere but I may have hold of entirely the wrong end of the stick or possibly completely the wrong stick.

I have cleaned, rebuilt, rebooted etc and it stills falls over.

I'm using Process Explorer (thats where the previous numbers came from) but can't seem to find VS in there to check what its total handle count is.

VS2017 on Win 11.

Yes, I have googled it and explored things to look at but I can't find a result that matches 'Studio falling over but the exe running fine', any help / pointers very much appreciated as I obviously can't debug the new form which does make things somewhat difficult.

CodePudding user response：

The underlying issue was to do with a pop-up form being generated by the parent form during its load processes, I found that the parent hadn't been issued a handle before it was trying to show the pop-up. Before you ask... I'm capturing data from a network sensor via the pop-up, which, once the user has accepted the incoming value, feeds the data back to the parent form. I assume that in run-time everything runs faster and it doesn't hit that 'un-coupled' point. Changed the code in the instantiate/load/shown cycle it runs and all is well.
Thanks once again Hans, headache solved.