Please run as root:
chmod a+x /usr/bin/fusermount
chown root /usr/bin/fusermount
chmod u+s /usr/bin/fusermount
Then try running the AppImage again, as a normal user. Does it work?
Please run as root:
chmod a+x /usr/bin/fusermount
chown root /usr/bin/fusermount
chmod u+s /usr/bin/fusermount
Then try running the AppImage again, as a normal user. Does it work?