Visual composer startup problem

Hi All,

   I have installed CE 7.1 trail version . Where I have to work on VC .I am giving follwing link to open VC

http://<hostname>:port/VC/default.jsp . It take me to the login page of VC and after successful login I am not able to see the next page. Its giving following error:

Could not open workspace due to following error:Kit menifestis bad or missing

tell me what to do

Thanks

Poonam Sharma