Application does not start: Can't mount devpts


flatpak seems to be very nice but I’m having trouble with my first installation. I have downloaded Delta Chat and it will not start with the following error:

bwrap: Can’t mount devpts on /newroot/dev/pts: Invalid argument
[2 preload-host-spawn-strategy] Failed to let stub process know of exit: Ungültiger Dateideskriptor (errno 9)

What could this mean or what can I do about this?

The best is to file an issue directly with the flatpak: