Unity3d plugin doesn't get loaded by firefox

I installed pipelight with the following commands:

sudo add-apt-repository ppa:pipelight/stable
sudo apt-get update
sudo apt-get install --install-recommends pipelight-multi
sudo pipelight-plugin --update

sudo pipelight-plugin --enable unity3d

But unity3d didnt't work or show up in about:plugins.

I also tried:

sudo pipelight-plugin --create-mozilla-plugins

and

touch $HOME/.config/wine-wininet-installer.accept-license
sudo pipelight-plugin --create-mozilla-plugins

to no avail.

When I start firefox after running --create-mozila-plugins it shows a popup that says it is downloading unity3d installer, it appears and dissapears 3 times.

The unity3d so file is present, running:

ls /usr/lib/mozilla/plugins

Prints:

flashplugin-alternative.so libpipelight-silverlight5.1.so
libjavaplugin.so libpipelight-unity3d.so

Silverlight on the other hand does work (--enable silverlight).