V5 is locking the folder where an STL you have loaded is located.
I turned off, disabled, the "Enable Live Reloading Of Model 3D Files"
Restarted the computer and S3D still locks the folder from which you have loaded an STL file.
Remove the STL file from S3D and the folder is still locked.
You can't move the folder.
You can't do anything with the STL file in the folder.
You can't save to the folder.
It is completely locked.
If I shut S3D down then I can do any of the above with the file or folder.