but yeah I’m not really sure what the issue is. On Ubuntu 16.04 it works fine for me. But I’ve never tried Ubuntu MATE. Maybe you could try using the binaries from TEST 11? I’m curious to see if you would get a similar issue when trying to run SAFE Demo App.
also, instead of using SAFE Launcher v0.9.2 (which should work fine), I would recommend using SAFE Launcher v0.9.3, as explained here: