I deleted that previous post because I was just reiterating earlier comments from various posts.
example: from long list of errors
Not the way to start an appimage.
A new day and I see xubuntu is being used so here is a little video running the appimage, start to finish including comments, 3 minutes. It might help
That is xubuntu 16.04 (Xenial)
I can even get the appimage running in PClinuxOS KDE, an rpm based rolling distro. Compatibility is never guaranteed but it is always worth a try.