Can't write new data after adding new column in table

[Jian0203]

Below is my original table in database which save customer login information.

CREATE TABLE IF NOT EXISTS `customerdetail` (
  `customer_id` varchar(20) NOT NULL,
  `customer_pass1` varchar(20) NOT NULL,
  `customer_pass2` varchar(20) NOT NULL,
  `customer_pass3` varchar(20) NOT NULL,
  `customer_pass4` varchar(20) NOT NULL,
  `customer_pass5` varchar(20) NOT NULL,
  `customer_email` varchar(20) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

Before the new column that allow users to upload their display image is added, my system works fine with the existing table.

PS: I use 5 password fields due to requirement.

After i add in the line below the add the new column ( display picture function ) :

ALTER TABLE customerdetail ADD customer_display blob NOT NULL;

Then my system can't write any data into the table anymore even i upload an "empty" picture.

Can anyone please verify for me what i did wrongly ?

Thank you so much for helping. I appreciate a lot.

[BubikolRamios]

You have to capture error message somewhere Higly rare situation would be : no error message.