Failed to process team: with Teams. Failed to find Team mailbox owner account.

When I try to backup O365 environment (Onedrive, MS Teams, Mailboxes and SharePoint) through Veeam backup server,  I received  the error that, Failed to find Team mailbox owner account and backup failed for the particular channel. 

The detailed error is below,

Failed to process team: <example_channel> with Teams. Failed to find Team mailbox owner account.

I found this group <example_channel> is orphaned  state, none is assigned as group owner. So I assigned one Global admin as owner to fix this. 

Follow the steps to assign Group owner,

1. Sign in to the Microsoft 365 portal with an account that has administrator privileges. 

2. Choose Groups from the navigation pane at the left hand side.

2. Search and find the group that you need to assign a new owner to and click on it.

3. In the new window appeared in right navigation, Select Owners tab, choose Edit.

4. In the View Owners dialog box, choose Add Owners.

5. Assign the right person(s) as owner and close the tab. 

Note : Select minimum two recommended as by MicroSoft.

Problem with attaching files in Teams chat or channel

 Error:

 When user is trying to upload files using MS Teams for a channel, getting files are locked error.

Cause :

The user does not have corresponding MSTeams channel site access.

Note: Every MS Teams channel has its own SharePoint sites. So when we upload files in MS Teams it will upload in SharePoint. So the affected users can verify themselves whether they have correct permission to access the MSTeams channel site access , click POSTS tab then  three dots (...) --> Open in SharePoint option. 

Solution:

Check respective MSTeams channel's SharePoint site permission for the user and assign required permission for the user.

Error: Failed to call RPC function 'StartAgent': Timed out requesting agent port for client sessions.

 Error : 

Failed to call RPC function 'StartAgent': Timed out requesting agent port for client sessions.

When we try to backup VMware VCloud environment, recently we occupied with above error in our Veeam server always, though these  environment (VBR and two repositories) have 200GB RAM and 2 sockets and 48 CPU cores on each servers.

This message typically means that the proxy/repository is overloaded, however all the servers are the Apollo servers, which most powerful machines with high configuration, finally I have lowered both proxy and repository tasks again and again, but the problem just reappear.

Cause:

There are transport agents that start for VMs processing's, this load can be limited by the concurrent task limit. 

But VCD job has also vApps, and for this container also transport agents start, but they are not limited by the concurrent task limit and Veeam Agent processes are not being properly closed by the moment so it is causing the port range (2500-3300) is being occupied. 

Due to this many agents are trying to start at one moment (we set 35-40 backup job start time as same) and  transport service "Veeam Data Mover Service"  started to crash.

Also we found some errors in log,

 < 34284> rpc      | ERR |RPC method call has failed (StartAgent).

 < 34284> rpc      | >>  |Timed  out requesting agent port for client sessions.

 < 34284> rpc      | >>  |--tr:Failed to initialize agent ( specified agent path: [C:\Program Files (x86)\Veeam\Backup Transport\x64\VeeamAgent.exe])

< 34284> rpc      | >>  |--tr:Failed to initialize agent instance {f392c303-9c2b-41dd-817f-6d04907ddf9e}.

< 34284> rpc      | >>  |An exception was thrown from thread [34284].

 

How to fix this,

We have moved some jobs from current backup time to another time, since then we haven't had a single failure. As talked with Veeam, this behavior was mostly unknown to them and they will take it up with QA. 

It must be much better to, do not start the agent until it is really needed, just like is the case already for VMs.