Bob
Some obvious ones - check how many RAILWORKS folders you have installed on any drive that could accessed by Steam.
Can you see the routes/ scenarios in \STEAM\steamapps\common\RailWorks\Content\Routes?
Ensure that there are not 2 entries for each route (one empty) - windows does that sometimes.
Close TS, Delete the files SDBCache.bin and the .MD5 file - open TS again - rebuilds the scenario db, are the routes visible?
Files found in \STEAM\steamapps\common\RailWorks\Content
Diagnostics:
Run sfc /scannow - any error messages?
Run dxdiag - any errors
Run DISM commands if necessary
https://support.microsoft.com/en-au/hel ... -readinesspH