If you receive the following when starting Exchange Server:
Event ID: 1002
Category: Internal Processing
Description: The Microsoft Exchange Server database, EDB, could not be initialized and returned error -1507. Unrecoverable error. The directory cannot continue.
Your Directory database, Dir.edb, is likely to have a damaged structure.
The recommended solution is to restore from a backup. If you can't, you can perform a full disater recovery of the Exchange Server. See the following: