I've just solved the error and it's working now
The problem was from the database
When a user inserts his info , there r some fields which r inserted with NULL .. not important information at registration phase according to the app requirements but he can insert them later when editing his profile
So I had to get that html error , I printed it using Toast to test and see what happens
The person responsible for the database created the columns to be NOT NULL
So the solution was : Removing the NOT NULL constraints of some columns