Can't install Sendy on Ubuntu 14.04 + Nginx + MariaDB (all logs attached)

I cannot get Sendy getting started on my Ubuntu machine. Despite following the Get started guide and checking all errors from Troubleshooting, I get an nearly white screen when trying to install.

I downloaded the latest version (v1.1.9.5), extracted it to a folder, set user rights for the whole folder to sudo chmod u+x *, set the rights for folder uploads to 777 and made sure that there are no empty spaces before or after the first line in the config.php file. Also, I double-checked that I did not put in wrong apostrophes in Vim.

Here is my server configuration and error logs (I changed my URL to server.com):

• Ubuntu 14.04.1 LTS
• PHP 5.5.9-1ubuntu4.5
• mysql Ver 15.1 Distrib 5.5.40-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2
• nginx/1.4.6
• Nginx Settings
• Nearly white screen
• Error log

What am I doing wrong? Any help is appreciated!