Trying to access the site, user is removed from usergroups to which he belonged

krileon wrote:

Previously that occurred normally, no modifications have been made on plans. Why now users doing login are removed from all usergroups?

They shouldn't be. CBSubs won't touch usergroups that it is not configured to control. It especially tries to make sure that the user at least always has Registered usergroup. Ensure your plans are only adding/removing the Subscribers usergroup. You may have something else configured changing usergroups if you're losing Registered on login.

We were using Step by Step registration. I tried Tabbed (horizontal and vertical) but no success.
I tried even with Flat registration, fields have reappeared but no Captcha has been shown.

That's because you have a Javascript error on your registration page. 99% of the time it's a 3rd party extension or Joomla template causing it or CBs jQuery was turned off. Follow my instructions are provide any errors shown in the developer tools console. You can check that CBs jQuery is enabled within CB > Configuration > Integrations by being sure "jQuery" is set to "Yes" and "jQuery Migrate" set to "No".

jQuery was set Yes in Integrations, and Yes in Migrate.
No changes when I set No to Migrate: Javascript doesn't work properly, even the info icons don't show the balloon...

this is the link:
qbquantobasta.it/registrazione

note: I changed the template to the standard, to "coolness", to "flexistrap", no way... Captcha doesn't appears, buttons don't work...

Looks like you're loading jQuery using Google CDN. My guess is that's being done with a 3rd party extension. Are you using any 3rd party Joomla extensions for loading jQuery? You should see such a plugin in Extensions > Plugins if you are. There are a few that modify Joomlas headers and block CBs jQuery from being output, which will break CB. The only workaround is to turn off CBs jQuery in CB > Configuration > Integrations (set "jQuery" to "No").

Now I tried to turn OFF jQuery and turn ON jQuery Migrate in CB Core...

Magically!

--> Captcha is enabled!
--> Birthday field has again the dropdown selectors!
--> AJAX password verify works!
--> info icons show balloons!
--> Step by step works!

BUT
still doesn't works "Show Password" button

Then:
Users are now again able to register and login
BUT
every time a user tries login, the site removes from Usergroup that user.

Ok, that confirms your issue isn't CB then. Something absolutely is modifying the header output of Joomla and removing CBs jQuery.

every time a user tries login, the site removes from Usergroup that user.

Please PM (see link in signature) backend super user login credentials and will take a look. It's unlikely CBSubs is causing this and is something else installed.

Have reviewed your install. This is not caused by CB. Same issue happens with Joomla user manager. Attempting to save any user there will log the admin out and wipe their usergroups. It's something else you've installed causing it.

Unfortunately there's nothing more I can do for you as it's not caused by CB. You'll need to find what you've installed that's doing this. I suspect it's one of the following as usually it's a User plugin acting on Joomla user events. Alternatively it could be a 3rd party System plugin as System plugins can also act on Joomla user events.

User - AIB - Author Info Box Profile
User - JComments
User - JFBConnect Social Integration
User - AltaUserPoints - New user
User - AltaUserPoints - Login Rule

Suggest unpublishing all of these, retesting, and seeing if that resolves your issue. If it does republish them 1 by 1 while testing after each one. Once it breaks again you'll have found the culprit. My suspect is the following since it impacts login and creation of a new user.

User - AltaUserPoints - New user
User - AltaUserPoints - Login Rule