Steps to reproduce

• create workflow, save it
• edit it in browser window 1 (neither save nor cancel, just keep it open)
• edit it in browser window 2 (neither save nor cancel, just keep it open)
• click cancel in windows 1
• click cancel in window 2

End result:

• workflow disappears from its workflow group

Suspicious item:

• the workflow version in table w_group_items seems to be stuck at a different version than the workflwo itself