Problems with Joining

Hi all.

I need some help urgently.  My website was working okay yesterday but now every time someone tries to register on the site they keep getting an explanation symbol when they click Submit on the Join Now form.

Even though the error appears, it does not show what field is causing the error.  It still comes up with the error no matter what is entered.

I have tried joining my website on multiple browsers, I have emptied my cache folders, and even put most of the profile fields as non mandatory, and still I cant register.

Does anyone have any ideas please?

Thank you kindly in advance.

 i would drag off all but username firstname lastname, email and password requirements, then one by one put them back on there. seems odd that the "exclamation" would show up near the login button, but not be reflected at which field is throwing the requirement.

something you have done has caused this situation, and you just need to think on what it was that you done, and try to reverse the action. 

The only things I have added is a CHAT MOD which was free from Boonex Market, and I brought a mod called MEMBERS ONLINE.

I have reversed both installations and it still is happening.  I am at a loss.