I had the same problem after yum updated horde. I restarted the server and all was good again? I suspected there were files in use or needed to be replaced.
Some templates needed to be expanded after the package updates.
Go to the Shutdown and Reboot panel and choose "Reconfigure". This is a new option which performs a "post-upgrade/reboot".
If you do the yum update from the command line, follow it with "signal-event post-upgrade" and then "signal-event reboot"
We are working on making this smoother, but for now, please ensure that you do one of these options if you have issues after updates. In most cases it's overkill, but it will ensure everything is expanded and restarted.