We've been notified about this issue and we'll take a look at it shortly.
The Phusion Passenger application server encountered an error while starting your web application. Because you are running this web application in staging or production mode, the details of the error have been omitted from this web page for security reasons.
Please read the web server error log to find the details of the error. If you don't know where the web server error log is, read the troubleshooting documentation below.
Alternatively, you can turn on the "friendly error pages" feature (see below), which will make Phusion Passenger show many details about the error right in the browser.
Phusion Passenger troubleshooting documentation:
To turn on friendly error pages: