Cannot delete user

Hi There,

I cannot delete or validate user from admin backend. getting message "could not delete the user". I had reninstalled the db and not getting better result. I have not changed any coding part only changed the design of login and registration page with keeping design in two sepreate folders. Some times it may cause the issue i mean ? any help appriceated.


Is there any plugin available to find out errors happening like above..Or the list of changes we had done previously ?