Quest Knowledge Portal (QKP) error when viewing any report: "Client found response content type of ", but expected 'text/xml'. The request failed with an empty response."
This could be for many reasons, but one such reason / workaround is below.
Sometimes, this issue is caused by having an older / stale Quest Knowledge Portal session loaded in your Web Browser. Try closing your Web Browser and navigating back to the QKP website and / or try "IISRESET" on the server hosting IIS / QKP and then close and open your Web Browser and navigating back to the QKP website.
Or look to the SQL Server Reporting Services database for any potential issues such as, insufficient disk space or the SRS service hanging on the SQL server.