Office 365: Unable to Open Archive Mailbox

In the recent hybrid migration, I experienced this so sharing with you all here.

This mailbox was a big mailbox with archive mailbox on Exchange 2013 in a hybrid setup.

We migrated this mailbox to office 365.

It got migrated perfectly. Absolutely no issues in migrating.

Outlook | OWA | ActiveSync connected as expected.

When user expanded the archive user got the following message popup

Issue:

Cannot expand the folder. The set of folders cannot be opened. Microsoft Exchange is currently busy. If this message is still displayed in 30 minutes, contact your Exchange administrator.

Resolution:

We waited for 30 minutes and archive mailbox started opening as expected.

Conclusion:

There is nothing to be panic here. Keep you cool and wait for 30 minutes.

This is one of the reason why we need to migrate mailboxes in the night or after business hours.

This is not an issue but it is by design.

Exchange Hybrid : Batch Migration

Exchange moved to more simplicity by the new feature of Batch Migration.

Batch migration is grouping of any number of mailboxes you would like to move. Rather than checking the status of all mailboxes one by one, you can view and run one command for whole batch.

I am sharing few points which you might be interesting in understanding.

1. In my customer environment, we had a batch syncing for 12 mailboxes. This is showing the status of the batch which is still syncing 1 mailbox to 95%. I have selected “manually complete the mailbox migration” so I will get a link on the right side when it will be ready to complete migration once sync will complete.

Now you will be wondering just for one mailbox whole batch will be waiting. Answer is yes if we wish to run a command for the batch but if we decide to run a command for other mailboxes which are in the auto-suspend status after 95% sync then we have to use PowerShell. Use this blog to connect to the office 365 powershell

Then to complete the migration of auto-suspend status mailbox we need to run the below mentioned commands

Set-MoveRequest “Display Name” – PreventCompletion $False

Resume-MoveRequest “Display Name”

2.  In another case, if you have started a batch mailbox migration and one of the mailbox has some issues which is why this mailbox sync has failed so out of hundred 2 have failed.

-Review the report which will show in the view details.

-Fix the issues with the failed mailboxes.

-Stop the sync

-Resume the sync. This will try the failed mailboxes again.