I downloaded the product from https://www.winzip.com/win/en/downec.html and debugged the behavior. I didn't have a luck to reproduce the crash, though.
WinZip Courier has a Firefox extension. Once I install and enable it, it launches its own process wzwmcffnm.exe and npwzwmc64.exe. The latter one wzwmcffnm64.exe injects npwzwmc64.dll into our browser process via CreateRemoteThread technique to customize the common file dialog.
For the "[ @ npwzwmc64.dll | GetModuleHandleW ]" crash, I think it happens during shutdown. Their code tried to use a pointer in a global variable in npwzwmc64.dll, but it was already set to null. This may be a timing issue that not every WinZip user hits.
According to https://www.winzip.com/win/en/contact.html, I sent an email to WinZip.