Hello 
I Could solve my Issue using this solution (Thanks to jtr) :
Connect to your VM (Shell Linux) hosting your NextCloud. Use SU.
Go to the Folder hosting NextCloud with the occ file. (This step should look evidence for everyone , but I am Noob hahaha, I give advices for Noob 
)
And write this :
Here , you can do this :
sudo -u www-data php occ files_external:list
You can see the bad External Drives and delete it with :
sudo -u www-data php occ files_external:delete X
Then , you can re-create good ones by using this command :
sudo -u www-data php occ files_external:create Blabla ‘smb’ password::password -c host=X.X.X.X -c share=/X/ -c root=/X/ -c domain=workgroup -c user=X -c password=X
Replace : X with Yours 
Have a nice day