There's a problem with STM Studio in the current Win10 update with "Controlled folder access" "security" nuisance.
For certain reason, Defender prevents STM Studio from opening its project and log files.
To properly fix this, STM Studio should have its Java launcher in the same way as CubeMX.does (and sign the executable files, please!).
Another issue is that in the recent update they changed location of example projects from Program Files to the user profile. But this again trips the "Controlled folder access". Because, the installer must run "as administrator" - therefore all examples are deployed into the user directory of Administrator. More to this - the actual user does not have access to the admin user profile so cannot get the examples. Better undo this change, or put the examples to Program Data.