PLEASE HELP database error when updating Duplicate entry '0' for key 'PRIMARY'

When upgrading a site to ee ver 2.11.3 I get to the final step and get this error: Database is good. What do I have to alter to remove this error?

A Database Error Occurred Error Number: 1062

Duplicate entry ‘0’ for key ‘PRIMARY’

ALTER TABLE exp_mailing_list_queue ADD PRIMARY KEY (queue_id)

Filename: libraries/Smartforge.php

Line Number: 353