Error msg duplicate entry - CLOSED

Am getting error message:
user warning: Duplicate entry '5-3' for key 1 query: INSERT INTO users_roles (uid, rid) VALUES (5, 3) in /var/www/vhosts/etc.../database.mysql.inc on line 172.

Just to brief you on my config. My test site has 10 users that were imported via user mgt/user imports. I've also used nodeprofile to create user profiles for each user.

I assigned membership-managed role and power user in site config/membership mgt. Then went to user mgt/membership mgt. to individually assign the expiry dates. That's when I got the above error msg.

Thanks for your help!