Recently install new Exchange 2019 in existing Exchange 2013/2016 org but unable to login to it’s ecp url and getting HTTP ERROR 500.
This is happenign becasue :
- Arbitration mailbox is still hosted on Exchange 2013/2016 server
- And Account used to access ECP does’t have on pre mailbox.
- Arbitration mailbox is used for anchoring of account without mailbox.
You can do either of these :
- Create a local mailbox on Exchange 2019 Database and assign that Org Admin Role
- Move Arbitration mailbox to Exchange 2019, which you might not feel comfortable until you decide to move your endpoint to new server.
Thank you for reading !