The problem is that I'm not familiar with "WP Customer Area" and I don't have any clue for this. The only thing I can recommend is disabling replacement of all login pages to wpForo login page in Dashboard > Forums > Settings > Features admin page:
And please explain what means the word "connexion", I don't know such word in English.
Well, my bad on the term "Connexion" it's the french syntax, and it means "Connection" (or "login" if you prefer) in english (not that far from the english term by the way...)
Anyway, did you read all the answers I've posted, because your last answer seems to turn in circle now as I've already written:
"My WpForo is already configured on 'No' for the 2 options 'Replace Registration page URL' and 'Replace Login Page URL' and works well on the website I'm working on when the 'WP Customer Area' plug is desactivated. And the 'WP Customer Area' plug works well too when WpForo is desactivated..."
This is not a small plugin to install and test. It should be configured exactly as on your website. Just let me know when you can provide website URL and admin access. This is the only way I could try to help you. You can send admin login details to support[at]gvectors.com. Also pleases send example URLs or other info which can help us find the problem.
Ok, so for now it's not possible, and the term and condition of the Site I'm working on will not allow me to give you any admin access...
You're right "Wp Customer Area" is not a small plugin, that being so, the configuration I use is just the default configuration...
I've just edited the WpForo special URLs custom authorisation on member tab to match the special login URL for Wp Customer Area plugin...