adding hyper-v host failed with "invalid credentials" noting that we dont have domain and the veeam and Hyper-v are on the same subnet

Hi @M.Mamdouh '

Welcome to the Community. Have you added your HV servers to the VBR hosts file? Also, make sure when adding, use the LOCALHOST\username format. Sometimes, updating the HV host, rebooting, then reattempting to add works.

Try those few things & let us know how it goes. 

@M.Mamdouh -

We discussed this issue at length in a previous post here on the Community Hub. I provided several other post links as well. The author of the below post shared what worked for him (DECOM security issue with Windows 2022, if you’re using that). You can go through the handful of suggestions there and see if any work for you:

Hi @M.Mamdouh -

Is KB5005102 installed? I believe it's an 'out of band' update to where you have to download it manually from the Catalog.

And, if you do have it, have you looked at all the other suggestions I provided above? You also should make sure UAC is disabled and verify Windows firewall is off, or proper rules set.

Let us know. 

UAC only needs to be disabled if a new administrator account is created. Else, he only needs to apply windows updates both on the HyperV and VBR server. Else, he might be missing other prerequisites which i have documented in that link above

Hi @M.Mamdouh . Yeah, we’ve had a couple posts by others on here with the same issue which shared all they needed to do was reboot, thus why I shared to try that first. Glad to hear it resolved your issue. And thanks for sharing what worked with the Community. Don’t forget to mark if one of the provided comments helped you resolve this, so others who may come across your post with a similar issue may benefit.

Best!