Module not found error

After around 2 years with no problems but today I got the below on start

venv "P:\Forge\stable-diffusion-webui-forge-main\venv\Scripts\Python.exe"
Traceback (most recent call last):
File "P:\Forge\stable-diffusion-webui-forge-main\launch.py", line 4, in
from modules import launch_utils
File "P:\Forge\stable-diffusion-webui-forge-main\modules\launch_utils.py", line 21, in
from modules_forge import forge_version
ModuleNotFoundError: No module named 'modules_forge'
Press any key to continue . . .

So I thought a total reinstall

but more module not found errors and failure installing Clip on reinstall

Start with the traceback in launch.py and modules/launch_utils.py, then reproduce the startup failure in the reported environment. Check the reinstall path and the separate Clip installation failure. Done means the application starts without the modules_forge error and the reinstall completes successfully.

Written by the indexing model from the issue text.