The notifications suddenly stopped a few minutes ago (without me doing anything), just as mysteriously as they started. I found the file you mentioned in the change log of my ownCloud sync folder and it was created today, then lasted for about an hour with updates every minute, before it was deleted again (alledgedly by me). I know that this file had never been in this folder before.
In the meantime, I was using Word, Endnote, Spotify and Firefox, without changing anything related to ownCloud, data syncronisation or even data on my computer in general, except from one word document saved elsewhere…