Hi,
someone changed the type of "firstname" and "lastname" fields from DB (correct is "text", so these fields are not shown on edit profile form.
These are core fields and are mandatory.

You can only disable lastname by changing in Easy Profile options the parameter "Name Style". But firstname is always required, because Joomla normal behavior require a name for the user.

Thank you. Works well now.

After making the change, it works well for the back-end.

However, when there is a registration, the form still asks for a First name field, though the first name info has been given. Please help.

Hi,
you does not use Joomla/Easy Profile registration form, now you use "Improved AJAX Login & Register" and it not have support for Joomla user plugins, so can create some problem with Easy Profile.

I think you need to contact "Improved AJAX Login & Register" support to find a solution, I know that many customer use this product with Easy Profile without problems.