Symptoms:

After you Synchronize users from Local Active Directory to Office 365 Directory using dirsync and try to enable users licenses on Office 365 portal you get the following error.

Error:

Exchange: Cannot process command because of one or more missing mandatory parameters: ArchiveGuid.Exchange: An unknown error has occurred. Refer to correlation ID: dfd8cc2d-e6a4-4b47-8e1e-2059031893c1

According to the error message, it indicates that parameter ArchiveGuid is missed, please refer to the following steps to narrow down this issue:

1.Please Connect Windows PowerShell to Exchange Online and run the command below to compare this parameter of users have errors with normal users:

$LiveCred = Get-Credential

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $LiveCred -Authentication Basic -AllowRedirection

Import-PSSession $Session

Get-Mailbox <username_with_errors> | fl archive* 

Get-Mailbox <username_no_erros>  | fl archive*

Apparently the commands above didn’t work. And so I had to check something else.!

In order to solve the problem first

1. I had to assign License to the user synced on O365.
2. Check User’s Proxy target attribute using ADSI. (Which was correct)
3. Checking Archiving Attributes since the error is mentioning the Archiving option.
4. After checking the Archiving attributes it turns that the admin of Exchange has changed the below attributes before he assign user the license on o365 and migrate the user. 

                    5. So deleting the value below msExchArchiveName and setting up msExchRemoteReceipeintType back to 4                             have solved the problem                    6. Of course DirSync needs to be applied in order to sync changes to AD on O365.

Note:

The migration for the User should be “continued” from previous migration batch in the portal otherwise if you start any new batch for the same user the result will be completed but migration won’t take place.

If you used DirSync to sync users from local to online, please try to restart the DirSync to check whether this issue persists or not.