What characters are you using?

Hi Cash, just when typing any name, I tried using only letters. There was no problem when creating the admin, but it doesn`t let users to register due to this error. Tx !

What characters are your users using?  If they're having problems, tell them to use only numbers and letters.

Hi Brett!, I`m only using letters and the same error appear. All other features are working fine in the site! Tx !

Have you installed any 3rd party plugins that affect the registration process?

Hi Brett, thank you for your reply, the enable plugins that are involve with the registration process  are uservalidationbyemail and profile_manager. I disabled them for testing but there is still the problem. : ( 

Do you know which check is being triggered?

Hi, I really didn`t know what happened but users can be added only by admin.

Now I`m testing 1.7.3.  I found something in this version, if the uservalidationbyemail plugin is disabled, users can register but Can`t enter, they appear as inactive users. If no confirmation is required users may enter the site after registration.  Is there any way/plugin to handle inactive users?

The embed plugin is making conflict with others also the Tools accordion menu doesn`t work if it`s enabled.