Can't offer much here, but I had fatal crashes with CMP, ending in "non responsives" from which there was no recovery. I finally deleted the whole kit and kaboodle, and re-installed Trainz from scratch.
When I was brand new to this I downloaded everything I saw basically, and at the time of the last hurrah, I had 1500 faulty items on my PC. CMP does not much care for these, nor do I for that matter. So when I say I deleted everything, I do mean EVERYTHING. Even though I have daily backups of the entire local folder, I chose not to re-install that (given all the mess I had, and you can't see what's what in the folders), but instead start ALL the way from scratch. I did have all my own stuff saved as cdp and archives, and I did re-install that.
Now I run a "clean show". I only download stuff I need, and I check it immediately for faults or missings. If they are faulty, and I really want them, they need to be fixed right away, if not, they get deleted. Yes, I had to re-download some things, but it was worth the time and effort. I have everything I need, and I have no (zero, nada) faulty or missing assets on my PC. And now CMP behaves. I do get the occational fallout (that's just CMP being CMP), but it comes right back up. I also get much better performance in Trainz now.
I know it's a royal pain to have to start over, I spent days and days cleaning up my act, but as I said, it was worth it. I also learned a few good lessons in the process.
Best of luck.