Agent v3 on Win7 "can't connect to remote backup service"

[millardjk]

TL;DR: has anyone else had issues with Agent 3.0 on Win7 being able to use VBR 9.5U4 as a backup target?
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No case associated with this; running NFR licensing, for which there's no support...

Have VBR & Win7 system that were happily working together with 9.5U3 & Agent 2.2; one of several Agent systems, although it's the only Win7 I have. Upgraded to 9.5U4, and the Win8.1 & Win10 machines all automatically upgraded Agent to 3.0, and are working as expected. Switched license from old-skool per-socket/per-agent over to instance-based, and everything happily started consuming instances at the new spec, both for the Agent backups as well as vSphere/VBR.
Except the Win7 machine.
It's been "incommunicado" (from the VBR server's perspective) ever since it was shut down prior to the upgrade. Manually upgrading to 3.0 didn't help; trying to get it to communicate with the VBR server results in a simple "failed to connect..." error. Have tried looking in logs, but unsure where on the Agent to find anything more than "error thrown" and where on the VBR server to see if there are more details on *what* error is being thrown.

Win7 system can otherwise communicate with the VBR server: ping responds as expected, UNC file requests (ie \\vbr\share) are functional. Firewalls are down on both for troubleshooting, and they're on the same Layer 2.

Personally, I suspect that there's a TLS issue, either with disabled ciphers or untrusted certificates, but I don't have any data to support that, nor do I know where to go to fix something like that if it turns out to be the case.

[doktornotor]

Have you installed this hotfix?

https://docs.microsoft.com/en-us/securi ... 15/3033929

[millardjk]

Yes; it's been on the system since mid-2015

[millardjk]

Aaand it's fixed.

I was using the trick of moving it to a new protection group in order to remove it from inventory (it was sitting in unmanaged). In the process, VBR pushed the MSI for the agent to the machine--was able to "talk" to it!--and after I deleted it, I could add it back to the protection group that I had for the other devices and everything was working nominally.

Looks like a combination of database issues (related to it coming from a per-Agent setup) and bad install/upgrade of the 3.0 Agent.