Few issues after changed Office 365 subscription from E3 to Business Premium

After changed subscription from E3 - Office 2016 to Business Premium - Office 2013, I ran into all kinds of problems. 

The first issue is the Office apps such as Word shows expired ProPlus license has expired even ProPlus has been uninstalled.

The 2nd issue is after the license issue has been fixed, I could not save files to SharePoint or Onedrive for Business in Word or Excel. It would keep prompting for login even I typed in correct credential.

Solution to 1st issue:

1. Run cmd as the admin

2. CD C:\Program Files (x86)\Microsoft Office\Office15 (Office 16 for Office 2016) or CD C:\Program Files\Microsoft Office\Office15  and press Enter.

3. Run cscript ospp.vbs /dstatus and press Enter (copy the last five digits of the product key for Office 16O365ProPlus).

4. Run cscript ospp.vbs /unpkey:xxxxx

Solution to 2nd issue:

Make sure "Modern Authentication for Office 2013" is enabled (Office 2016 is enabled automatically).

Check the registry and make sure those two keys below present.

Registry key	Type	Value
HKCU\SOFTWARE\Microsoft\Office\15.0\Common\Identity\EnableADAL	REG_DWORD	1
HKCU\SOFTWARE\Microsoft\Office\15.0\Common\Identity\Version	REG_DWORD	1

https://docs.microsoft.com/en-us/office365/admin/security-and-compliance/enable-modern-authentication?view=o365-worldwide

Yes confirmed today

SHE is a bitch!

After mailbox migration to O365, the mailbox did not move to disconnected mailbox

We have been migrating mailboxes from on-prem Exchange 2010 to O365. All was good except two mailboxes. After migration was successful, these two mailboxes did not move to 'disconnected mailbox' status as they should be. Therefore, all external emails and O365 went to O365 that users can view them in OWA and on-prem emails went to their Outlook because Outlook is connected to on-prem Exchange automatically instead of O365.

Solution: (by Awesome MS support)

1. Disable the mailbox in Exchange Management Console on Exchange 2010 or use the command below. My case I use GUI.

Disable-Mailbox -identity -<user_identity_email>

2. Issue the next command

Enable-RemoteMailbox "<user_identity_email>" -RemoteRoutingAddress "<user@mydomain.mail.onmicrosoft.com>"

3. Run a Azure delta sync - (or full sync)

Start-ADSyncSyncCycle -PolicyType Delta

Start-ADSyncSyncCycle -PolicyType Initial

4. Create a new Outlook profile which should connect to O365.