Symptoms: 

Task steps are assigned as configured per workflow and at some later time the task steps are assigned to random workflow roles in addition to the configured one.

Explanation: 

One database change related to a stored procedure was missed for database upgrade script in WS 10.4.5 and task steps were reassigned when a user was added to certain groups. All releases done after WS 10.4.5 are having this issue.

Resolution: 

You can fix this issue on ORACLE database by deploying the updates to WorldServer 10.4.5, 11.0 and 11.0.1, available on FTP.

If you cannot deploy it, contact the SDL Support Team:

•     Log on to your "My SDL" Account.
•     Log a support request via Support & Education Support. 

Notes: 

• All systems running WorldServer 10.4.5, 11.0, 11.0.1 and using ORACLE Database,  MUST have this hotfix applied.
• The fix for this issue is available in WS 11.1 too.