If you use phpmyadmin, just find your table “wp_wsluserscontacts”; Display its structure; find the “email” field and click on Modify.Click on the null Checbox and save. Or do the following command:
ALTER TABLE wp_wsluserscontacts
CHANGE email
email
VARCHAR(255) CHARACTER SET latin1 COLLATE latin1_swedish_ci NULL;
If you are not familiar with phpmyadmin, find someone who is… ??