Ich hab da im Technet was gefunden...
Error ID number: c1030af0
Error Message
The operation failed due to an invalid format in the HTTP request. Verify that the host header is correct for the virtual server.
Possible Causes
This error can occur if you have multiple IP addresses bound to the network card on the Exchange server and you have the default Web site bound to the secondary IP address.
An invalid host header or IP address has been set for the default Web site
Incorrect IP addresses or host header is set on the cluster virtual server.
Troubleshooting
Try setting the default Web site to All Unassigned and then reopen the ESM and try to expand public folders.
Correct the host header value or remove it completely.
bloss weiss ich jetzt nich wirklich wie das geht...
wo kann ich das einstellen dass die Standard Website nicht bestimmt ist?