Forwarding any signed and/or encrypted mail as attachment will cause the error `The orginal item must be saved before the operation can be completed`:
{F27909152}
To reproduce:
1. Select any signed and/or encrypted mail
2. Click "... / Forward as Attachment"
{F27909488}
This behavior can be seen at least since version `vsd 3.1.26`.
Debug log:
{F27909438}