The content cannot be displayed in a frame - Exchange On-Premises - Exchange Online - Exchange Hybrid

After setting up your Hybrid Exchange connection and logging in to the Exchange Control Panel trying to move your first mailbox to Exchange Online you need to login to Office365.

When you click the login button on the popup you receive the following error:

Now this is fairly easy to fix, just add the url https://outlook.office365.com to the trusted sites in Internet Explorer.

But then this:

The option is greyed out.

There are 2 ways to get around this, one through the registry and one through a group policy:

Add the following to a textfile and paste in:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMapKey]
"https://outlook.office365.com"="2"

Save as a .reg and execute.

This can also be stored in the HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMapKey.

The check if the settings are present run in PowerShell:

$(get-item "HKCU:\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMapKey").property            
            
$(get-item "HKLM:\SOFTWARE\Policies\Microsoft\Windows\CurrentVersion\Internet Settings\ZoneMapKey").property            

The group policy goes like this:

• Start -> type gpedit.msc -> hit Enter
• navigate to Computer Configuration -> Administrative Templates -> Windows Components -> Internet Explorer -> Internet Control Panel -> Security Page
• in the right-hand panel, double-click on the Site to Zone Assignment List option, then click Show...
• trusted sites are the ones with 2 in the Value column (1 = Intranet, 3 = Internet, 4 = Restricted)

If that doesn't work (that option is set to "Not Configured" or the list is empty), try the same, except instead of Computer Configuration, start with User Configuration.