Issue Summary

JQL Search for assignee on members of a group with user without assigned ticket gives error:

A value provided by the function 'membersOf' is invalid for the field 'assignee'.

Steps to Reproduce

1. Create a group and add a test user with no assigned tickets
2.  Use that group name in the JQL search below

(assignee changed FROM membersof("Group1")) and (assignee changed TO membersof("Group2")) and (request-channel-type=portal) 

Expected Results

Either issues are found or none depending on current system stats

Actual Results

JQL reports a problem

A value provided by the function 'membersOf' is invalid for the field 'assignee'.

Workaround

Assign and unassign any issue to user A. Although, it changes the state a bit, the problem appears only if affected user was never assignee of any issue.