Icon only showing if insync started as sudo

I am using Ubuntu 18.04 and my insync app does not start either clicking on the insync icon or starting the app via terminal. It does only if I try to run it via sudo. Anyhow I only see the icon in the top notifications bar of gnome but the application itself only shows as a blank box when clicking on the icon.
Any help on troubleshooting this? Where can I find a useful log?

Hi Paolo,

Sorry for not replying sooner! Can you run sudo apt-get install sni-qt, reboot your PC, and then run insync start --no daemon? Send us the output afterwards. Thanks!