I had this problem when I installed QVS 9 using IIS7 webserver and as solved the problem including the QVSTunnel in IIS. IIS Manager -> ISAP and CGI Restrictions -> Add
ISAP or CGI path -> C:\Program Files\QlikView\Server\QvTunnel\QVSTunnel.dll
Description -> QVSTunnel
Mark check box -> Allow extension path to execute reestart IIS I hope that this will help you.