@briannippert Thank you, but unfortunately it didn't work for me, I tried G1000 @ 172, deleted/created/changed the flight plan and even loaded app procedures but it didn't work, it will keep crashing. So, this lead me to more digging:
After the hint related to flight plans being loaded or not will cause the TMB 900 to crash, I went to look for those files related to saving the flight plans, so I Google around and I found that those files should be stored somewhere in here: \X-Plane 11\Output\ . So I tried all short of things and finally, I decided to delete everything (including my joystick and all my settings, which I backed up of course!) and... the TBM worked again!!!! Such a relief, after my real airplane broke last week TMB 900 is my only fix.
So, I went back and restored everything and again, TBM crashed, as expected. So I least I was able to reproduce the problem. I started to individually delete folders and that lead me to "\X-Plane 11\Output\preferences", the only one that after deletion I was able to use the airplane again.. So, I individually deleted every single file inside but it didn't work........... So, I went back, deleted everything again, booted without my settings, used TMB (without any problems), then close X-plane and explored the newly generated files and I noticed "fms-0.fml" and "fms-1.fml". So I copied them, restore my old preferences folder and replace the "fms-0.fml", which was alone, for some reason "fms-1.fml" didn't exist in my original/old "setup". I booted again and viola! TMB 900 is working again with my old settings...
So, I'm attaching the files here, just go to \X-Plane 11\Output\preferences\ and place or replace "fms-0.fml" and "fms-1.fml" with the ones attached here and try again, it worked for me. I'm also attaching "fms-0 (INOP).fml", which is the broken file not letting me play in case somebody wants to do some "NTSB" forensics. I hope it helps somebody.
Side topic, I found this very interesting video that explains what the "Inertial Sep" switch does (TMB 900):
fms-0 (INOP).fml
fms-0.fml
fms-1.fml