If an Exchange system has been running for a long time, the database can reach the maximum limit of named properties or replica identifiers. When migrating this will result in a (500) Internal Server Error message.
You can identify this by checking the Exchange Event Viewer, looking for Events 9666, 9667, 9668, and 9669.
If the database has reached the named property or replica identifier quota limit and an attempt is made to create a new named property or replica identifier, the error Events will be logged in the event log. The named property or the replica identifier will not be created successfully
The easiest way to resolve this is to increase the named property limit in the Registry on the Exchange server.