​​​@m.saleh 

Was the hyperv server l been added with IP or netbios name?

are the veeam server and respective hyperv server on the same lan\vlan?
maybe it doesn't resolve because the error is access denied propbable you don't have Admiistrator permissions.
Or simply communication blocked by local firewall.
 

• Disabled the hypervisor firewall?
• Have you tried disabling UAC on the windows hyperv?
• is the veeam server multhomed?

Thank you

Hello,

Was the hyperv server l been added with IP or netbios name? IP Address

are the veeam server and respective hyperv server on the same lan\vlan? Same VLAN 

The user is in Local Administrators group

Firewall is disabled

UAC is diabled

Is the Hyper-V server on the domain?

Can you try with the built-in Administrator account?

as recommended by @HangTen416 

Try using the local Administrator account of the HyperV server.

es: .\Administrator

Yes, very probably is a credential error or missing the “.\”
Let us know!

Did you install Veeam Backup & Replication on the Hyper-V server itself - or on another system?

It may work that way -but is not a good idea.

Hello. I have the same problem. I have Windows Hyper-V Server 2016. Updates were installed yesterday and I think the problem is in KB5014702

Like this update broke a working cluser?

I have error in eventlog DCOM 10036

"The server-side authentication level policy does not allow the user %1\%2 SID (%3) from address %4 to activate DCOM server. Please raise the activation authentication level at least to RPC_C_AUTHN_LEVEL_PKT_INTEGRITY in client application."

Reason and solution: https://support.microsoft.com/en-us/topic/kb5004442-manage-changes-for-windows-dcom-server-security-feature-bypass-cve-2021-26414-f1400b52-c141-43d2-941e-37ed901c769c

You can also see: https://forums.veeam.com/veeam-agent-for-windows-f33/dcom-hardening-on-windows-server-june-cu-t81317.html

Thanks for sharing @b.s.  → Product Management is aware and they may provide an update on the Forum site.

Yes it’s on Domain

I tried with the build-in Administrator account but didn’t work, also tried to create a local user with administrative privileges but didn’t work. 

Didn’t work

Actually i tried with both `.\` and `HOSTNAME\` but didn’t work

Veeam is installed on a separate server.

Yes I’m getting this error in the Event Viewer at the Host side (Hyper-V) but actually I don’t know what the exact value to fix this issue for the DWORD: RequireIntegrityActivationAuthenticationLevel to be 0 or 1 and this registry should be added in both sides Veeam and Hyper-V ?

Sorry for being idiot but really this like pain 

DWORD: RequireIntegrityActivationAuthenticationLevel = 0 on Hyper-V host and restart this

Hello,

I have a Hyper-V host with 2012 R2 on it and already added to Veeam as a host and it was working fine.

One day I found a VM backup job fail.

I tried to rescan the host and found the error 

Access Denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

I tried to edit the host and check the credentials and found 

I removed the job and removed the host and tried to add it again but the same error in image above appears.

I don’t know where the issue comes from. The credentials are the same didn’t change 

 

Regards,

Muhammad

i have same problem.

this DWORD: RequireIntegrityActivationAuthenticationLevel = 0 on Hyper-V host and restart is valid?

Hi, it could quite well be. It’s discussed in this KB:

https://www.veeam.com/kb4376
 

If it seems to relate to your environment it’s worth testing. Otherwise read the logs to get an idea of what’s going on in your environment.

But server i check no this upate patch

To confirm you mean the OS patch isn’t at least June 2022?

Thanks, refer to https://www.veeam.com/kb4376  this action after reboot is work!

I had the same issue, it was resolved after updating windows on VBR. 

Good afternoon, I'm having the same problem. Not being able to understand our friend @wllam  and our friend @bari19 , you did the Windows and VBR update is it? Could you explain better the solution found? Thank you very much!

I did notice that to resolve this issues, both servers must be 100% patched and upto date, dont try any other changes, until both the physical servers have been patched and are upto date with the same patches applied, Reboot both severs twice - bingo, should all be working.

I had add the key RequireIntegrityActivationAuthenticationLevel=0  as the article said and rebooted the Hyper-v server ,but the error was still there .