Navigate to Dashboard > Forums > Tools > Debug Tab, click on link, compare with the list of wpForo tables and let us know how many tables are not installed. 

It's a problem of your plugin

@sofy

But I do not lose the forum doing so?

No but you should ALWAYS have a full backup (WP and DB) in any case. Any change (even an update) can ruin your installation. Does happen often but it happens.

If you have a Cpanel, a full backup takes 5 minutes to complete.

But I do not lose the forum doing so?

If you don't have important information I'd recommend you to deactivate, then Uninstall (not a simple Deactivation, use the Uninstall button to remove all forum data). Then delete the wpForo plugin, search and install it again. 

Thanks, I sent what I said to the email you gave me

please register some new user and send the login details with your forum URL to infogvectors.com email address to allow us to check it. 

I put the code but I get a lot of errors, also there is another problem to make a topic asks me to register or login when I'm already logged in ... 

I do not know

Please try the solution mentioned in this support topic, just let us know if it doesn't help.

https://wpforo.com/community/how-to-and-troubleshooting-2/topic-add-error/#post-6511