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Expected Behaviour:
Be presented with the web interface at 192.168.1.11/admin
Actual Behaviour:
Presented with a blank page, no error displayed and the page's source code is empty. I have tried a fresh install, no luck. Ad blocking works and can access limited options via terminal. I have tried in different browsers and on different devices but same result. I have ran "sudo git status" and found no corrupted/modified files.
I made a test.php file in the same directory and got the same result. It seems the issue is with lighttpd. Possibly something to do with the php sockets?
It looks like your version of PHP is missing an API and also can't access a directory:
2017-11-17 23:32:34: (mod_fastcgi.c.2543) FastCGI-stderr: PHP Warning: session_start(): open(/var/lib/php/sessions/sess_diof5ns73aa83fcjaduomr5697, O_RDWR) failed: No such file or directory (2) in /var/www/html/admin/scripts/pi-hole/php/password.php on line 10
2017-11-17 23:32:34: (mod_fastcgi.c.2543) FastCGI-stderr: PHP Fatal error: Uncaught Error: Call to undefined function json_decode() in /var/www/html/admin/scripts/pi-hole/php/update_checker.php:12
Make sure the www-data user has read/write access to /var/lib/php/sessions.
It seems that your packager for PHP decided to remove the JSON library. Add it with apt-get install php7.0-json and run sudo service lighttpd restart (I assume this is the correct package name).
