ExceptionInInitializerError when launching the launcher

The launcher crashes immediately when I start it with a ExceptionInInitializerError exception, caused by a SecurityException, itself caused by a NullpointerException.

I'm not sure what version of the launcher I'm using because I couldn't even get to the launcher's home screen : it crashes immediately. There's no "Linux" version so I chose the java one.

I have no idea what the cause is. It's a fresh Ubuntu install. I've tried with OpenJDK 8, with no success.

The full log shown in the launcher is attached.