Ubuntu 18.04

[skull87]

I had to do this for libpng

 

apt-get update

apt-get install libpng12-0

 

Than do this for mono to get it to work fully

 

wget http://www.tcadmin.com/installer/mono-2.11.4-x86_64.ubu.deb
apt-get update
dpkg -i mono-2.11.4-x86_64.ubu.deb
apt-get install -f
/opt/mono-2.11.4/bin/mozroots --import --sync --quiet
/opt/mono-2.11.4/bin/mono --aot -O=all /opt/mono-2.11.4/lib/mono/2.0/mscorlib.dll
for i in /opt/mono-2.11.4/lib/mono/gac// /*.dll; do /opt/mono-2.11.4/bin/mono --aot -O=all $i; done

[eirsik]

Mono 2 is not supported anymore on the new updates. You should install mono 5