Show error message for mandatory fields in registration

If there's a page to test on, it would help narrow things down quickly. JFBConnect uses the form-validate tag on the form and the validate.js script from Joomla to mark any fields that aren't set with the proper CSS tag.

I believe the fields that aren't set properly will be updated with a class like the below:It's up to your template to properly set a style for the 'invalid' class.

I hope that helps, but if not, please let us know where we can test and we'll gladly investigate further.

Thanks,
Alex

My request then is to have some kind of text to tell the user that the input is required or invalid, is that possible?

We don't have an easy way to do this right now. However, the following line of code is in plugins/socialprofiles/communitybuilder/communitybuilder.php around line 126. It adds a star to the field to show that it's required and could be modified to have more verbose text.
That combined with highlighting the input that's invalid should help do what you're looking for.

I've added an issue to our tracker to make the * a string in our language files.

-Melissa