Guys, basicly I'm doing an Installation of OpenProject 5.0 with Apache on Ubuntu 14.04. LTS

https://www.openproject.org/open-source/download/manual-installation-guide/

Starting from a untuched machine with ubuntu 14.04

at the "Serve OpenProject with Apache and Passenger" part
 when i try to connect on port 80, i got this as result

"We're sorry, but something went wrong.
We've been notified about this issue and we'll take a look at it shortly."

Does any1 has any clue about what went wrong and how can i fix it?

Thank you for reading.