Just to say, that i have the same problem with a blank screen, with a droplet on digital ocean.
I had it working on a previous droplet fine, but this time i have tried to configure fastcgi & opcache has turned on.
(Duplicator) Installer.php with an archive.zip and database.sql.
I an trying to work out what happened, but at the moment i'm at a loss. Any ideas ?
The Ubuntu 13 php does not come with json installed.
sudo apt-get install php5-json
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
0 upgraded, 1 newly installed, 0 to remove and 14 not upgraded.
Need to get 19.8 kB of archives.
After this operation, 119 kB of additional disk space will be used.
Get:1 http://us.archive.ubuntu.com/ubuntu/ saucy/universe php5-json amd64 1.3.1+dfsg-2 [19.8 kB]
Fetched 19.8 kB in 0s (25.3 kB/s)
Selecting previously unselected package php5-json.
(Reading database ... 94254 files and directories currently installed.)
Unpacking php5-json (from .../php5-json_1.3.1+dfsg-2_amd64.deb) ...
Setting up php5-json (1.3.1+dfsg-2) ...
php5_invoke: Enable module json for cli SAPI
php5_invoke: Enable module json for fpm SAPI
php5_invoke: Enable module json for apache2 SAPI
php5_invoke: Enable module json for cgi SAPI
root@the-great-divide:~# apachectl restart
Then my installer.php worked.
I worked this out by starting in the ssh shell on the server
root@xxxxxxxx:~# php installer.php
PHP Fatal error: Call to undefined function json_decode() in /root/installer.php on line 117