Try resetting the default program to open that kind of file by checking the box to always use this app to open it.
I've done that, and I have opened the part, done a full rebuild and saved it again, and it still wants to crash unless I use that 1 way to open it.
I appreciate the suggestion made.
Oh it's showing up in the Event Viewer:
Faulting application name: SLDWORKS.exe, version: 18.104.22.168, time stamp: 0x4f72d57a
Faulting module name: CWPPMu.dll, version: 0.0.0.0, time stamp: 0x4f7ab4e2
Exception code: 0xc0000005
Fault offset: 0x000000000004c9bc
Faulting process id: 0x1554
Faulting application start time: 0x01cd402a3321a58e
Faulting application path: C:\Program Files\SolidWorks Corp\SolidWorks\SLDWORKS.exe
Faulting module path: C:\Program Files\CAMWorks2012x64\CWPPMu.dll
Report Id: 7b5c28c6-ac1d-11e1-98bf-386077cd7095