Virtualbox Debian repository requests 5.1.24, but it doesn't exist, prevents system update -> obsolete

[Fuquay]

When attempting to update my system (Ubuntu 17.04, 5.1.22), the Virtualbox Debian repository requests VirtualBox 5.1.24. However, it doesn't exist. *This error in the package definition prevents systems that use the repository from receiving ANY updates (without manual intervention) - not just VirtualBox.*

E: Failed to fetch http://download.virtualbox.org/virtualbox/debian/pool/contrib/v/virtualbox-5.1/virtualbox-5.1_5.1.24-117012~Ubuntu~zesty_amd64.deb  404  Not Found [IP: 88.221.50.105 80]

Note: A workaround that allows the system to be updated manually is to add the --ignore-missing flag to the apt or apt-get command.

[Fuquay]

This appears to have been fixed. VirtualBox 5.1.24 has been made available. (The URL is my report above no-longer reports a 404 Not Found status code, and I have been able to upgrade.)

[Fuquay]

I spoke too soon. On launching VirtualBox 5.1.24 for the first time I was prompted to install the extension pack, which resulted in "The network operation failed with the following error: During network request: Url not found on the server." It seems that there are still missing or inaccessible 5.1.24 resources for the moment.

[Fuquay]

The update process, including installation of updated extension pack and guest editions, worked fine on a separate machine a few hours later. I'm happy for this to be closed again.