I was last month in the middle of an SBS2003 to SBS2008 migration, using the Swing Migration method, when a family issue forced me to hand over the job in progress to another individual for completion. Now I am back in the saddle and the customer is having problems with Exchange 2007 SP1 (rollup 10 installed). Specifically, they are having problems both sending and receiving emails *sometimes*, some of the Exchange services will not start after an update, and there are quite a few Exchange errors in the event logs. I had hoped to revert to the point in the migration where I'd left it but the indiviual in quesiton overwrote the backups I'd made AND formatted the TempDC I was using so I have no fallback. The TempDC is still listed in the AD and is also the routing group master. Using ADSIEdit I see may references to it but haven't changed any of them for fear of doing further damage. It's such a mess I'm tempted to start from scratch but the client doesn't want that!
I am hoping someone here can help me with this. The very first error I see in the Applicaiton Event Log is
CertificationAuthority 91 "Could not connect to the Active Directory. Active directory Certificate Services will retry when processing requres Active Directory access."
MSExchange ADAccess 2114 "Process MSEXCHANGEADTOPOLOGYSERVICE.EXE (PID=1552). Topology discovery failed, error 0x80040952 (LDAP_LOCAL_ERROR (Client-side internal error or bad LDAP message)). Look up the Lightweight Directory Access Protocol (LDAP) error code specified in the event description. To do this, use Microsoft Knowledge Base article 218185, "Microsoft LDAP Error Codes." Use the information in that article to learn more about the cause and resolution to this error. Use the Ping or PathPing command-line tools to test network connectivity to local domain controllers."
There are quite a few more if you want them.