HydraPaper doesn't list any wallpaper

[thefuga]

As title says, HydraPaper can't find wallpapers. I specified folders which contain jpeg images but nothing is displayed.
When launching from terminal, i get the following warnings:

(hydrapaper:2): dbind-WARNING **: 17:21:58.511: Couldn't connect to accessibility bus: Failed to connect to socket /tmp/dbus-vVhWFASkHT: Connection refused

(hydrapaper:2): GLib-GIO-CRITICAL **: 17:21:58.700: g_dbus_proxy_new_sync: assertion 'G_IS_DBUS_CONNECTION (connection)' failed

And this is what the app shows:
https://i.imgur.com/yOPGU76.png

I'm running from Ubuntu Budgie 18.04 and installed HydraPaper from flatpack (following all steps described in the readme). In case it matters, i'm using one 1080p monitor connected with DVI and one 720p monitor connected with VGA.
I've also tried to run as root but no wallpaper was listed aswell.

[Viry0ne]

Hi all, any comment on this issue ? got the same, running on ubuntu mate 19.04
From terminal got Gtk-Message: 03:07:00.147: Failed to load module "appmenu-gtk-module"