Had issue with changing from a Generic Request to an Enhancement.

The reason was because I had set the security tab to only allow visibility and editability for the ITG administrator. This meant that users were not able to move (edit) the workflow field from Generic to Enhancement. Proposal worked because there was no restriction against any user at all. The other point that is important is that all statutes need to be in place. It will result in the same problem if a workflow status is missing.