Ubuntu 14.04 LTS Grav installation not working

I am brand new to Grav and I created a brand new pair Networks, pairCloud server, running Ubuntu 14.04.04 LTS:

Linux gwpair1 4.2.0-34-generic #39~14.04.1-Ubuntu SMP Fri Mar 11 11:38:02 UTC 2016 x86_64
PHP Version 5.5.9-1ubuntu4.14

I installed the basic Grav under my altoplace.com domain: /var/www/altoplace.com/grav

When I go to http://altoplace.com/grav, I get a white screen.

I have the EXACT same configuration set up on my Mac. I just rcopied the files to my pairCloud server. Grav works on my Mac, but not on my pairCloud server. The biggest difference is my Mac is running PHP 5.6.19, but the pairCloud server is running PHP 5.5.9, which I thought was the minimum required. I either installed the required PHP extensions or tried to verified that the extensions were enabled already:

http://altoplace.com/info.php

http://altoplace.com works and is using some very basic php for the page menu and footer.

Can anyone confirm that my pairCloud configuration “should” work, and, if so, would you have any suggestions why it is not working? In a month or so I am plannin g to upgrade my pairCloud server to Ubuntu 16.04 LTS, when it is officially released. I believe that it will support a much newer version of PHP.

Thanks much,
George

Ok, digging a little deeper, I found this in my error log:

[Sat Apr 02 13:51:36.964789 2016] [:error] [pid 15308] [client 50.151.248.137:42275] PHP Fatal error: Uncaught exception ‘RuntimeException’ with message ‘Creating directory ‘/var/www/altoplace.com/grav/cache/compiled/files’ failed on error mkdir(): Permission denied’ in /var/www/altoplace.com/grav/vendor/rockettheme/toolbox/File/src/File.p hp:400

May be I don’t have an apache2 configuration option set correctly. This doesn’t look like a PHP version issue. I will dig some more.

Ok, sorry for the trouble. It was a file permissions error, which I fixed according the Trouble Shooting section of the Learn document. It’s working now.