Very weird problem. When starting TSC the screen resolution immediately resets to 640x480 and only the top left quarter of the loading and menu screens are visible. I tried forcing higher resolution through Steam’s executable shortcut. I tried doing a file verify. Neither works. This is the only one of my Steam games affected. Any thoughts??
In File Manager find a file called PlayerProfiles.bin in the folder that has TS in it and delete it. (The file not the folder!) The file stores your settings and when you next start TS it will make a new one with best guess settings so you may need to change things back the way you like them. A corrupted PlayerProfiles.bin file can cause all sorts of problems and it does seem to be fragile. Assuming you do make changes I'd suggest storing a copy of it somewhere once you have things the way you like them- it'll save you some clarting about if your settings get screwed up again. (Clarting is a north east of England word- it is not rude.)