I changed the path of the project using venv, so it didn't work properly.

I thought it worked successfully because there was a (venv) on the terminal line.

However, the __VENV_DIR__ in the 

set "VIRTUAL_ENV=__VENV_DIR__" 

in the activate script did not work properly because it was the PATH before the replacement.

How about adding a procedure to verify the __VENV_DIR__ is a valid PATH to the Activate Script?