Comment 2 for bug 554640

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 517505, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.

As noted in bug #517505, the workaround for this problem is:
1. Quit the Ubuntu One client. From the applet select Quit. Then open a Terminal (Applications > Accessories > Terminal) and run the following to quit the syncdaemon.

u1sdtool -q

2. Delete the old metadata. In a Terminal run.

rm -rf ~/.local/share/ubuntuone

3. Start Ubuntu One as you normally would Applications > Internet > Ubuntu One