"Application is not responding" during upgrade with Tails Cloner
On Tails 6, when applying the new Tails version to a 64 GB USB drive using the Tails Cloner, I repeatedly got the "Application is not responding | Force Quit | Wait" dialog while Tails was writing to the drive I updated. The drive I updated had a persistent volume.
Repeatedly clicking "Wait" resolved the issue, and the drive was successfully updated.