I've recently applied SP1 to a clients Exchange 2010 server & the ECP has stopped working. Browse to https://servername/ecp
from the server and i get Server Error in '/ecp' Application, Input string was not in a correct format.
Browse to it from any other machine and the the error screen looks slightly different, generic OWA screen which says
An error occurred and your request couldn't be completed. Please try again.
I've had a search about and can only find one or two people with this same problem and they seem to have fixed it by remving the ecp vdir and recreating it, i've tried this and it doesnt work.