Cannot open metadata input/ output stream.
I have been using Acronis for more than ten years. On this network we have Windows PCs and a Netgear NAS, Acronis 2019 runs on a Windows 7 64-bit PC. We have a local backup of the NAS storing the backups to a USB hard drive, We have two other backups storing PC backups on the NAS. These all work fine.
The Acronis Cloud backup of data on the NAS has been running smoothly for months, storing files and folders on Acronis' Cloud storage. Suddenly this week, for the Cloud backup only, we see "Cannot open metadata input/ output stream." The local backups are running smoothly. The local backup is for the same file set for which we see errors when backing up to the Acronis Cloud.
I have tried creating a new Cloud backup set for just one file. Same error.
What to do, experts?