ICS synchronization failed

[Anuj]

Hi Guys, I'm having some issues with the O365 Public folder backups.
Processing mailbox XXXX failed with error: Failed to synchronize item changes in folder: GAL Contacts.. Access is denied. Check credentials and try again., ICS synchronization failed. :: 0:13:08
The error seems to be occurring when trying the process the GAL Contacts and Recipient Cache folders - problem is I cannot locate these folders (under ipm and non-ipm)
Have checked and Permissions seem fine.

Have logged a support tic but not had much luck
Case #05072056

Any help would be appreciated

Thanks

Anuj

[Polina]

Hi Anuj and welcome to Veeam Forums!

In your case, there's a note that you were limited to 10K results. Can you try using the "-ResultSize Unlimited" parameter in the request to list all the folders?

Thanks!

[Anuj]

Thanks for getting back to me. I did run that command and unfortunately still cannot find any reference to those specific folders

[Polina]

Is there no reference in either IPM and Non_IPM subtrees?

[Anuj]

Yes correct.

[Polina]

Anuj,

I've asked VBO support engineers to take a closer look at your case. Please stay in contact with support to continue troubleshooting.
Thanks!

[Anuj]

Thanks for your help Polina,
This has now been resolved.
Veeam support recommended using EWSeditor to check the structure of the Public folders and this helped us identify permissions issues in some of the many subfolders.

[Polina]

Awesome!
Thanks for posting; I hope this will also be helpful for those who run into a similar issue.