Sorry for the delay. I am checking with the team on this issue now and will report back here once I hear from them. Thanks.

Thanks and no worries, the backup plan works fine, it's just the sync. This appeared after I had to restore my PC to a previous state, using an imaging tool. Explorer had become unstable and the quickest fix is to restore the system disk to a date where it was OK.

it's a known issue with 7.0. There is a work-around, but you'll lose history and you'll need to re-sync your data. Since it's in Glacier, if the backup is working, I'd recommend waiting for the 7.0.1 release which is planned to address the issue.

Thanks a lot, I'll wait for next version then !