Hiya, Got an annoying problem here - just migratedto Exchange 2007 (from 2000) onto a new server. As the old Ex2000 server was also a DC which had Windows 2000 on it, I first had to remove all the mailboxes, then remove Ex2000 from the machine and AD, then demote it as a DC. I then installed Ex2007 on new server, all went OK. However, I am getting a 'Read only MultiValuedProperty does not support this operation' error when trying to (re)create the mailboxes for existing users. If I completely add a new user, it's fine! Any suggestions? Thanks/...

Don't worry - managed to fix it.! Thanks anyway...

What did you do to fix it?

I used ADSI Edit to copy/pastethe msExchVersion value from a working user to a non-working user, as it was blank for all non-working users.