Same here.
I had an older SVN on top of 0.2.3.RC3 when I first got this error yesterday. Hadn't changed anything for many weeks, and it had worked well before this. I suppose the problem is either in corrupted database or in some corrupted config file, as this started after MP had crashed couple of times.
I uninstalled everything and installed MP 0.2.3 with SVN 16600 and TVServer SVN 16600.
Didn't help...
TV Server config -application doesn't work properly (not able to export or import channel list, not able to delete channels etc).
I have deleted all channel data and program data (directly from tvlibrary database with SQL-editor) and recreated it with TVServer config.
Did not help...
Maybe I have to uninstall everything once again and also clean up all old files and folders.
Mine now works. I am using a version of the client from 17 Oct and the server from 14 Oct (by the exe dates) and they seem to almost work properly. I think I uninstalled everything and cleaned up as much as I could find, maybe even removing the database. I think it is just a matter of reinstalling enough but I still think it is an issue that is is so easy to get into such a mess
I found where the problem was. There was one corrupted table in the database (I think it was table "programs").
I deleted the whole tvlibrary database instance and then reinstalled all MP components. Now everything works again.
Of cource it would be nice, if the system had found out there is a problem with the database and either informed user about it or even fixed it itself.