Failed to connect to Installer service

[JChen522]

Veeam Case# 07600665

We have two veeam servers, one running v11 VEEAM-1 and one running v12 VEEAM-2. We also have couple proxy servers running v11. We are in the middle of moving jobs from v11 server to the v12 server. We didn't want to risk failed upgrade of existing servers because there are many repositories and jobs.

For some strange reasons starting last week, we started getting this error when we try to restore files using the v11 server or try to browse the property of VEEAM-1 Backup Proxy agent.

"[VEEAM-1] Failed to connect to Installer service.
Backup server version 11.0.1.1266 is not compatible with Installer serviced on VEEAM-1"

I get an error "Logs export failed" if I try to generate tech support information.

We contacted support but the case was immediately closed because v11 is not supported any more?

Add/Remove Program on VEEAM-1 server which is v11 shows the following version.
Veeam Backup & Replication 11.0.1.1261
Veeam Backup VSS Integration 11.0.1.1261
Veeam Backup Transport 11.0.1.1266
Veeam Distribution Service 11.0.1.1266
Veeam Mount Service 11.0.1.1266

What would it say Backup Version is 11.0.1.1266 when add/remove program says it is 11.0.1.1261?

What could be the cause of this issue and how to resolve it?
Thanks you!

[david.domask]

Hi Jimmy,

By chance are you sharing any components (proxy, repository) between the two servers? Very likely, one of the DLLs in C:\Windows\Veeam got replaced on the server in question -- you can confirm this by checking C:\Windows\Veeam\Backup and checking the Properties > Details of the VeeamDeployment.dll file there.

https://www.veeam.com/kb2263

The solution from this article should help, ignore that the article is about HyperV. Once the KB is followed, then go through the properties on the v11 server.

> We contacted support but the case was immediately closed because v11 is not supported any more?

Support is correct here, v11 is End of Support since Februrary 2024. Sharing components across installations can result in situations like this as noted in the User Guide

[JChen522]

That article worked! VeeamDeploymentDLL.dll was somehow updated to 12.2. Once I removed the service and rebooted and browsed the property again. It updated to the correct version. Thank you so much!

[david.domask]

Hi Jimmy,

Glad I was able to assist and glad to hear it's working again.

I will remind briefly about not sharing components between multiple Veeam servers, as this very often will create such situations and can potentially lead to data loss. (Imagine backups on a repository shared between two Veeam servers getting acted on at the same time, or someone accidentally mapping backups to jobs on two different servers, not good!)