( Max7 | 2018. 10. 28., v – 17:04 )

root@debian:~# mount /dev/loop1p1 /root
mount: wrong fs type, bad option, bad superblock on /dev/loop1p1,
missing codepage or helper program, or other error

In some cases useful info is found in syslog - try
dmesg | tail or so.
root@debian:~#