I have a backup job that is over 1TB of data, it has taken a long time to get all the data uploaded to the cloud backup. and now i have 17,865 files that can not bet uploaded. The error in the history report says the following for all of the files.
Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host.
There could be several reasons for that error, including problems with Backblaze services and AV/FW issues. Usually this message is the result of some other issue, so it would be better to send the logs to support for proper log investigation.