Backup can't be uploaded

Installation
1

I have a problem—I can't upload my backup. The moment I click "Upload," I get the following error:

error (mainthread) [supervisor.api.backups] can't write new backup file: connection lost

I can't upload the same backup to my old instance either, but I can start a restore from it. See screenshots:

Bildschirmfoto 2026-07-07 um 10.14.08
Bildschirmfoto 2026-07-07 um 10.14.082938×1764 213 KB

I'm a bit lost; I can't
Backup file is 10 GB big. However, I've uploaded backups as large as 30 GB in the past without any problems.

2

Im pretty sure this is not the only "line" you got in your Log.
If you click /Setting/system/logs you find " 3 Dots " to the right of the log-overview.
Click that ( RAW -Log ). (you can even get further details, if you enable "Debug" for the Backup Component/Integration)

Also make sure you have available space on your backup-storage.