Unable to update Webmin

Some of my servers update with no problem, but some fail with error:

.. update failed : Installing package(s) with command /usr/bin/yum -y install wbm-virtual-server.noarch webmin.noarch ..

Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
 * base: mirror.spreitzer.ch
 * extras: mirror.spreitzer.ch
 * updates: mirror.spreitzer.ch
Resolving Dependencies
--> Running transaction check
---> Package wbm-virtual-server.noarch 0:5.03.gpl-1 will be updated
---> Package wbm-virtual-server.noarch 0:5.04.gpl-1 will be an update
http://SERIALNUMBER:LICENSEKEY@software.virtualmin.com/gpl/universal/repodata/6440b912f3ff0a923aae535409b06404d3680883-filelists.sqlite.bz2: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
To address this issue please refer to the below knowledge base article 

https://access.redhat.com/articles/1320623

If above article doesn't help to resolve this issue please open a ticket with Red Hat Support.

Error: failure: repodata/6440b912f3ff0a923aae535409b06404d3680883-filelists.sqlite.bz2 from virtualmin-universal: [Errno 256] No more mirrors to try.

.. install failed!

Any advices on how to resolve this?