We are migrating from Exchange 2010 on-premise to O365. Currently I have a hybrid environment. I am down to my last few users to migrate and I have 4 that have the same error every time I try to migrate them. The error is: More than one ComponentShared mailboxes exist for this user. To prevent Primary mailbox from coexisting with ComponentShared mailbox, this MailUser cannot be converted into a mailbox.
The users all exist on-premise and are in the cloud because of syncing between on-premise and cloud.
I have found an article: https://social.technet.microsoft.com/Forums/en-US/fc0ddfea-442c-4cce-9a10-9e18cdb3fdb4/error-recieved-during-hybrid-migration-more-than-one-componentshared-mailboxes-exist-for-this-user?forum=onlineservicesexchange
Using the info in the article I have confirmed that the above error is true. The article says to delete the user in Azure AD/O365 by using the following command: remove-msoluser -userprincipalname <firstname.lastname@example.org>.
So I have a couple of questions. First, if I can successfully do this, will that also remove them from on-premise AD? This would be a bad thing. Second where do I do this at? I have tried, successfully, to use the Azure AD Power-shell installed on one of my hybrid environment to connect to the O365 environment. But every time I attempt to run that command against a test user who also has been synced to the cloud with no mailbox at present, it fails as an unknown command. Thinking that it might be the capitalization of the command, I had found another article with different capitalization and that still didn't make any difference.
Anyone have an idea how to resolve this issue so that I can move the mailboxes?