this error pop ups if UTC timestamp on peers differs by more than 10 minutes. All peers shall have it the same, taking into account their local time and timezone, so check these in first place. Re-sharing a folder will not help here.  This article will help to to verify the timestamps . To avoid further misunderstanding, I'll provide some comments ahead. UTC time shows the devices time relatively to Greenwich.  So if peerA is in (UTC +01:00), and peerB is in (UTC +03:00) time zone, the l