Reinstalled the game today and it crashes at start. Saw some people getting the same issue on this forum. Lazy to post my answer to everyone's post without a solution.
How i solved it (maybe it will work for you too)
WindowsMenu > Parameters > Update & Security > Windows security > Protection against ransomwares > Manage protection against ransomewares > Allow an app through a controlled access to folders
Or just type Controlled folder access in Windows menu / Parameters
Then allow :
-Steam.exe
-Tabletop Simulator.exe
(should be in recent blocked apps if you're too lazy to browse your Hard-Drive)
This solved the Steam Sync error too for me.
Hope it will help.