Hi, and welcome aboard!
I am not sure what your problem is.
The general rules for saved games in SH3GWX and listed in the GWX manual, and most relate the the problems with SH3 and not GWX.
Don't save in the harbor or near land (50Km)
If you save with a lot going on (under attack, near a convoy, submerged,
damaged, impending air attack, etc.) the save will not work, and the game will CTD (as it will in "vanilla"SH3)
If you do anything in mid patrol to your install (add a mod, remove a mod, etc.) you are risking a CTD upon loading any saved game.
Some people have stated that if you save and then immediately save again, this will prevent CTD on reloading the save.
As stated above, it is a good rule to run a shakedown cruise on your first patrol in a new career.
And, of course, you need to have SH3CMDR.