[Clippings] Error massage

[Christian]

When opening Clippings-Manager, I get following warning
massage:

[Exception..."Component returned failure code: 0x8000ffff
(NS_ERROR_UNEXPECTED)
[nsIRDFService.GetDataSourceBlocking]"nsresult: "0x8000ffff
(NS_ERROR_UNEXPECTED)"location: "JS frame ::
chrome:clippings/content/clippings.js :: init :: line 161"data:no

All of my saved entries are gone.
Also, I can't create new entries.

Any insights?

Greetings,
Chris