In the default setup as well as in the Live ISO, FUSE is not functional due to
wrong fusermount permissions, giving:

fuse: failed to exec fusermount: Permission denied

A workaround is to run, as root:

chmod a+x /usr/bin/fusermount
chown root /usr/bin/fusermount
chmod u+s /usr/bin/fusermount

Tested with openSUSE-Tumbleweed-GNOME-Live-x86_64-Snapshot20170524-Media.iso.

References:

https://github.com/probonopd/AppImageKit/wiki/FUSE

Perhaps an openQA test could be added to ensure that FUSE is working
out-of-the-box.