T12 randomly deleting objects and session

Been working on a route for a long time. Played it for a while like several weeks and decided to make small changes to the route. I get on and first thing I saw the session I was using got deleted. I didn't really think about it since I had other sessions saved so I used another one. I went and started to make changes then a few days into the tweaking. I load the game to find HALF OF MY ROUTE OBJECTS AND TRACK WAS GONE! The only thing that remand was the boards and textures. I tried using another older session and this time instead of a intact session like last time. I get on to find yes everything minus the expansion objects and track gone (No big deal) but to find like my route layed track all over THE DAMN PLACE! Tracing the track it was linked to where the expansion started but instead of going where I placed it it decided to go across the other way and link up to various other places on my route. I tired creating another session by loading the route itself but that file everything was practically gone. I tired seeing maybe the route and session layers were merged and they were. I tried running the repair asset on Content Manager which had no luck. I know when I saved the sessions it would give me a error saying I couldn't save the file because it was thinking it was a read only file which saving it again fixed that. But I doubt that error would be the cause of the stuff getting deleted. Anyone got a clue on what is going on? I hate to give up on something I worked for half a year on

This to me sounds like you've edited a session instead of the route. If you make changes in one, it's not reflected in the other.

Go to the layers and merge the session into the route, save (do a save as to a new name for safety), and see if that works.

In the future do your route editing on the route only, which should only contain things that are static such as track, buildings, textures, trees, etc.

Sessions should be used for operations and things that require configuration such as portals, trains, driver commands, etc.

As stated in the post. I tried Layer merging with no success.