Not tried it, but I suspect this is working as designed - not sure import/export of OVFs with ISO's attached to the VM is meant to be supported.
You can almost certainly get around it by:
- Take a backup copy of all the files in case something goes wrong...
- Edit the VDA01.ovf file with a text editor and remove the reference to the ISO file.
- Delete the VDA01.mf file (since the manifest will contain a reference to the ISO).
- Upload the VM OVF (without the ISO).
You should then be able to separately upload the ISO to a catalog and re-attach it to the VM.
My feedback here would be that if ISO uploads in OVF is not supported, then the dialog should be changed to reflect that, and allow an upload even without the ISO file and remove the references automatically. As it is now, users would just be confused on why it's not working.
What I did to fix this was to use VMware converter to export everything, and then import it with ovftool, and that worked much better