the Cell hasn't started.
If the website is blank, that means that Tomcat has started but nothing else is actually running.
Cell.log is just a high level overview of the services starting. vcloud-container-debug.log will have the more explicit details.
Please make sure you meet all the requirements for starting the cell. Forward and Reverse DNS is required, and validated on start up.
if you could attach that log, we might be able to help.