Failed to access public folders

[N19901]

Hi,
We are encountering this error in 2 clients backup.
[Error] Processing mailbox@client.onmicrosoft.com failed with error: Failed to access public folders.. There are no public folder servers available.
has anyone an idea.
we are running the following version: 7.1.0.2031 P20240418

[Mildur]

Hello N19901

Do you have the necessary permissions applied?

- Exchange Online license for the specified user in the M365 organization registration:
- Owner Permission on Public Folder for this user
- Azure App Permission: Office 365 Exchange Online > Exchange.ManageAsApp
- Azure App Permission: Granting Global Reader Role to Azure AD Application

Please contact our customer support team if all permissions are applied. Don't forget to share the case number with me.

Best,
Fabian

[N19901]

Hi Fabian,

Case #07304594
My colleague has completed all the steps and set the permissions correctly. However, we are now facing a different issue: the job containing the public folder keeps running without transferring any data.

The official backup job containing the public folder is stuck and has been running for over 24 hours, while it usually completes in about an hour. I created another test job on a different proxy, but it is also running without processing any new data anymore.

[Mildur]

Hi N19901

Your Public Folder backup may be affected by this known issue:
https://www.veeam.com/kb4577

Best,
Fabian

[N19901]

Hi Fabian,

Thanks for your reply!

I have already checked that, and we are going to execute it. However, it seems more like a workaround than a permanent solution to the problem.

Kind regards,

[Mildur]

According to my information there was a change on Exchange Online (change made by end of April 2024). It affects all third party products working with this specific API calls.
For now the kb article is the only solution we can provide.

Best,
Fabian

[Polina]

I'd only add that the situation is highly unlikely to improve, and we expect to see more complications and limitations to PF backup coming in the future.

[AlexL]

Thanks for the heads up Polina,

Even if I do understand Veeam's position I'd like to add that the suggested solution alters a feature or functionality of public folders. For us no issue, this time, but still not happy about this.
Also, if there would be a large environment that still uses public folders, casually running the provided command might have serious consequences or functionality wise simply not possible to do.
I'd suggest adding appropiate warnings/disclaimers, in rare cases the solution might be worse than the original issue.