Veeam Backup for Microsoft 365 • Re: Failed to upgrade proxy agent

Case #07795948
Same issue while upgrading from version 7 to 8.
AV disabled, firewall down.
The servers are in Workgroup domain and local admin accounts are in use.


The sequence:

[26.08.2025 11:56:37.653] 36 (1) [Info] Proxy pool version upgrade started
[26.08.2025 11:56:37.653] 36 (1) [Info] Proxies upgrade started
[26.08.2025 11:56:37.654] 22 (1) [Info] Proxy upgrader thread started
[26.08.2025 11:56:37.654] 22 (1) [Info] Prepare proxy server upgrade
[26.08.2025 11:56:37.654] 22 (1) [Info] Proxy configuration:
[26.08.2025 11:56:37.654] 22 (1) [Info] Host: proxy1
[26.08.2025 11:56:37.654] 22 (1) [Info] Port: 9193
[26.08.2025 11:56:37.654] 22 (1) [Info] Username: proxy1\admin
[26.08.2025 11:56:37.654] 22 (1) [Info] Version: 7.1.0.2031
[26.08.2025 11:56:37.654] 22 (1) [Info] Supported proxy pool version: 1
[26.08.2025 11:56:37.654] 22 (1) [Info] Upgrading proxy (ID: 12eb3f27-0449-40f9-aebc-967247a0daf1)...
[26.08.2025 11:56:37.670] 22 (1) [Info] Updating of the pooled backup proxy server is still in progress (backup proxy server: 12eb3f27-0449-40f9-aebc-967247a0daf1).
[26.08.2025 11:56:37.670] 22 (1) [Info] Checking credentials on host: proxy1...
[26.08.2025 11:56:41.485] 14 (1) [Info] Resuming (attempt number: 1)...
[26.08.2025 11:56:42.399] 16 (1) [Error] Error: Handshake failed. Reason:Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host..


Already increased the timeout from 60 to 300 on backup and proxy servers.

On the proxies, I got this on Event Viewer under Security:

A privileged service was called.
Subject:
Security ID:proxy1\admin
Account Name:admin
Account Domain:proxy1
Logon ID:0x49985
Service:
Server:Security
Service Name:-
Process:
Process ID:0x748
Process Name:C:\Windows\System32\svchost.exe
Service Request Information:
Privileges:SeTcbPrivilege

Statistics: Posted by soramanego — Sep 01, 2025 6:35 am

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