I upgraded from 4.10 to 4.11 (with openSUSE 12.3) and found that all my nepomuk tags have disappeared from the files they were added to; the list of tags is still intact, but I can't add tags to files either. So in dolphin, right click on a file -> properties -> information -> add tag, I add a previously created tag, click okay and no tag turns up in the dolphin file list (with tag field showing), when I right click again and go to the information tab the tag is missing. I also cannot create new tags, in the add tag filed I type in a new tag, check it, click okay, but it does not get saved to the file, and it is not in the list of tags if I try to add it again.

I have tried copying my old /.kde4/share/apps/nepomuk/repository/ directory, backed up when still running 4.10, replacing the current directory (with nepomuk disabled, and after logging out and back in). This restored my tags, but I cannot add old tags to files or create new tags.

I would be grateful for any suggestions for getting nepomuk working properly again.

Can you please tail ~/.xsession-errors, and attempt to add tags to a file and see what is output?