Q: Unable to activate iCloud Drive on OS X Yosemite 10.10.1

Hi, I'm unable to activate iCloud Drive on my MacBook running Yosemite 10.10.1. Some documents eventually show up in my iCloud Drive, but I'm never able to create new ones or download new ones created e.g. on the web or on my iphone. I disabled iCloud Drive for now, and whenever I try to re-enable it I get the following erorr in the Console:

cloudd: SQL error: 'DELETE FROM CSChunkTable WHERE ct_iid = 596', (11) database disk image is malformed

which is repeated for 100s of ids. iCloud Drive works on a guest account and on other devices. I already tried signing out of iCloud on this Computer, but without success.

Is there any way to "repair" this malformed database disk image? Any help would be greatly appreciated.