Launch TC
Draw 3D object and save it in STL format
Close file and go to File > Open
TC hangs when trying to select file.

Close TC and restart it
TC hangs every time on trying opening the Open dialog.


Solution: 


It is Windows 8 & 10 issue.
The workaround to avoid issue on the computer (do it once):
Open any STL file by program that is specified by default for the STL extension once (mouse double click on file).