Error mounting /dev/sdb1 at /media/bart/Debian 8.5.0 M-A 1: Command-line `mount -t "iso9660" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,iocharset=utf8,mode=0400,dmode=0500" "/dev/sdb1" "/media/bart/Debian 8.5.0 M-A 1"' exited with non-zero exit status 32: mount: /dev/sdb1 is write-protected, mounting read-only
mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.