If you haven't updated your version of Virtualmin/Webmin for a while and you encountered this error when you tried to update - e.g. from version 4.12 to the current version 4.17:
[Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found" Trying other mirror.
See the screenshot below: It usually means the yum cache-files are stale, i.e. the location of the required files for the update has changed. To fix this, run: # yum clean all # yum check-update That will refresh the yum cache. Once that is done, you can run update again from the Virtualmin interface or simply run the update command from the commandline: # yum update