Exchnage 2019 ECP. Unable to access user mailbox via the Exchange ECP after Migration

Son2020 45 Reputation points


i need Help

After migrating some mailboxes from Exchange 2013 to 2019, i am unable to access the user's mailbox via the Exchange ECP by selecting another user from the dropdown menu in the upper right corner, Error Message 4003 forbidden.

But if i select a user whose mailbox is located on Exchange 2013 Database works.

And in Event Log i get this error Message

Event id 4 Exchange control Panel
System.Web.HttpUnhandledException (0x80004005): Eine Ausnahme vom Typ "System.Web.HttpUnhandledException" . ---> Microsoft.Exchange.Management.ControlPanel.UrlNotFoundOrNoAccessException:

owa and ecp work


Exchange Server
Exchange Server
A family of Microsoft client/server messaging and collaboration software.
1,059 questions
Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
7,328 questions
0 comments No comments
{count} vote

Accepted answer
  1. Jarvis Sun-MSFT 10,091 Reputation points Microsoft Vendor

    Hi @Son2020 ,


    According to your description, I found a similar case that mentioned the problem was that the permissions of the Default role assignment policy for a user's mailbox went wrong during migration. The solution is to manually create a new Default policy and assign it to the mailboxes:

    New-RoleAssignmentPolicy -Name NewRBAC -Roles
    @("MyBaseOptions","MyProfileInformation","MyContactInformation","MyDistributionGroups","MyDistributionGroupMembership","MyVoiceMail","MyTextMessaging","MyRetentionPolicies","My Marketplace Apps","MyTeamMailboxes") -IsDefault:$True
    Get-Mailbox <identity> | Set-Mailbox -RoleAssignmentPolicy NewRBAC

    User's image

    Please refer to: Exchange 2016 ECP - "Another user" access broken
    Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

    If the above info does not work, please check the following elements:

    1. By “owa and ecp work”, do you mean the users can directly log in to the ECP page successfully?
    2. Test whether other administrator accounts have the same results
    3. Check if you have the same permission on both the problematic database and the Exchange 2013 Database: Get-MailboxDatabase db01 | get-ADPermission -user [admin01@contoso.com]

    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

    1 person found this answer helpful.

1 additional answer

Sort by: Most helpful
  1. Amit Singh 4,846 Reputation points

     I think you should confirm these first:

    1. Do all these migrated users couldn’t login to OWA? Can they login to EAC(ex2013.domain.com/ecp)?
    2. Have you tried to recreate the OWA and ECP virtual directory like I posted above? Reset the internal/external URL to ex2013.domain.com/owa and try it.
    3. Please check if you are using the Exchange 2013 OWA to login(ex2013.domain.com/owa).

    Recycle MSExchangeECPAppPool and MSExchangeOWAAppPool in Application Pools from IIS Manager.

    Otherwise, you can create a new mailbox of Exchange 2013(choose Ex2013 database when creating) and test if he can log in to 2013 OWA.

    Also you can check this link for help - Cannot Access ECP on New Exchange 2019 Server