Exchange Admin Center (EAC) or Exchange Control Panel (ECP) error ‘Access Denied’

When you try to log on to Exchange Admin Center (EAC) or Exchange Control Panel (ECP), you receive an error message that resembles the following:

2898912Analysis of the issue

Run the following cmdlet and see if the mailbox shows the error is listed on the result:

Get-Mailbox -ResultSize Unlimited | Where { $_.RoleAssignmentPolicy -like $null}

Solution

Assign the ‘Default Role Assignment Policy’ to all the mailboxes in the list:

Get-Mailbox -ResultSize Unlimited | Where { $_.RoleAssignmentPolicy -like $null} | Set-Mailbox –RoleAssignmentPolicy “Default Role Assignment Policy”