Hi Mark;
In all my past experience with PB versions and various Apps, this usually ties back to a few things - especially when the App runs OK in the debugger. The Debugger can change the event firing order, delay when events are fired and/or slow the event function processing down (allowing other things to complete).
Here are a few suggestions:
1) if its a PFC App, make sure that you download and apply the latest PFC build that matches PB2017R3
2) Look for PowerScript in the Open event that uses MS-Windows SDK calls.
3) Look for code in the Activate, Deactivate, System Mapped, or Other events that try to do something on Window instantiation.
4) Look for code in Window "Controls" like Constructor, Get/LoseFocus, System Mapped, or Other events that try to do something with other objects. If these other Controls (or the object itself) are not properly instantiated, you can get a failure message or even an App crash depending.
5) Watch out for DW Control scripts on RowFocusChanged, ItemFocusedChanged, or special System Mapped "DW" events that fire at instantiation time.
5) Try commenting out the above script(s) until the App crash stops
6) Move the incriminating code on the suspected event(s) to an later event. For example: PostConstructor or PostOpen
Note: Remember that event firing order changes every now and then across a PB release due to new features being added to various object classes. This has definitely occurred in the PB 8, 10, 11.5 and 12.0 PB versions. So it is a quite common change. As PB developers, we need to keep this in mind when coding current Apps.
HTH
Regards ... Chris
