In order to overcome this issue, you must become the default publisher yourself by following the steps below:
Alternatively, other users from the virtual appliance contact list can become default publishers by following the instructions above, as long as they own a personal access token and have permissions to manage the virtual appliance.
NOTE: If this issue is kept unresolved for a long time, it is possible that the continuous delivery backend will automatically pause the process, until manually resumed by the author.