Hi Keybdflyer When you Reinstalled everything did you run your GWX Game first so if makes a SH3 Folder in your documents for your Campaign Career Saves.
On the Commander mod theres a check box use authentic Uboat availability dates uncheck it then click apply every option you change you must click apply so changes you have made become active & all should be well ok
Just to recap re Commander Mod Configured so your SH3 Game Folder looks like this the GWX.EXE Icon & the GWX Commander Config Icon if you played your campaign a few years ago & have now reinstalled it but you have not installed the commander Config Files
then that's why your crashing from your Sh3 Career