There is a USB-HDD which was detected as HDD until ~27.07.2017 after this it is detected as CDROM. And so the system try to mount as -t iso9660. This failed because the HDD has a ext3 partition ...

The same behavior in LEAP 42.3 as in LEAP 42.2!

Below the output from udiskctl:

08:07:00.122: Added /org/freedesktop/UDisks2/drives/ASMT_2115
  org.freedesktop.UDisks2.Drive:
    CanPowerOff:                true
    Configuration:              {}
    ConnectionBus:              usb
    Ejectable:                  false
    Id:                         ASMT-2115-0x5000000000000001
    Media:                      
    MediaAvailable:             true
    MediaChangeDetected:        true
    MediaCompatibility:         
    MediaRemovable:             false
    Model:                      2115
    Optical:                    false
    OpticalBlank:               false
    OpticalNumAudioTracks:      0
    OpticalNumDataTracks:       0
    OpticalNumSessions:         0
    OpticalNumTracks:           0
    Removable:                  true
    Revision:                   0
    RotationRate:               -1
    Seat:                       seat0
    Serial:                     
    SiblingId:                  /sys/devices/pci0000:00/0000:00:14.0/usb4/4-5/4-5:1.0
    Size:                       1000204886016
    SortKey:                    01hotplug/1502345220121239
    TimeDetected:               1502345220121239
    TimeMediaDetected:          1502345220121239
    Vendor:                     ASMT
    WWN:                        0x5000000000000001
08:07:00.122: Added /org/freedesktop/UDisks2/block_devices/sdb


/org/freedesktop/UDisks2/block_devices/sdb:
  org.freedesktop.UDisks2.Block:
    Configuration:              []
    CryptoBackingDevice:        '/'
    Device:                     /dev/sdb
    DeviceNumber:               2064
    Drive:                      '/org/freedesktop/UDisks2/drives/ASMT_2115'
    HintAuto:                   true
    HintIconName:               
    HintIgnore:                 false
    HintName:                   
    HintPartitionable:          true
    HintSymbolicIconName:       
    HintSystem:                 false
    Id:                         by-id-scsi-35000000000000001
    IdLabel:                    CDROM
    IdType:                     iso9660
    IdUUID:                     2015-08-06-17-37-43-00
    IdUsage:                    filesystem
    IdVersion:                  Joliet Extension
    MDRaid:                     '/'
    MDRaidMember:               '/'
    PreferredDevice:            /dev/sdb
    ReadOnly:                   false
    Size:                       1000204886016
    Symlinks:                   /dev/disk/by-id/scsi-35000000000000001
                                /dev/disk/by-id/scsi-SASMT_2115_56A01000000000000403
                                /dev/disk/by-id/wwn-0x5000000000000001
                                /dev/disk/by-label/CDROM
                                /dev/disk/by-path/pci-0000:00:14.0-scsi-0:0:0:0
                                /dev/disk/by-path/pci-0000:00:14.0-usb-0:5:1.0-scsi-0:0:0:0
                                /dev/disk/by-uuid/2015-08-06-17-37-43-00
  org.freedesktop.UDisks2.PartitionTable:
    Type:               dos



/org/freedesktop/UDisks2/block_devices/sdb1:
  org.freedesktop.UDisks2.Block:
    Configuration:              []
    CryptoBackingDevice:        '/'
    Device:                     /dev/sdb1
    DeviceNumber:               2065
    Drive:                      '/org/freedesktop/UDisks2/drives/ASMT_2115'
    HintAuto:                   true
    HintIconName:               
    HintIgnore:                 false
    HintName:                   
    HintPartitionable:          true
    HintSymbolicIconName:       
    HintSystem:                 false
    Id:                         by-id-scsi-35000000000000001-part1
    IdLabel:                    CDROM
    IdType:                     iso9660
    IdUUID:                     2015-08-06-17-37-43-00
    IdUsage:                    filesystem
    IdVersion:                  Joliet Extension
    MDRaid:                     '/'
    MDRaidMember:               '/'
    PreferredDevice:            /dev/sdb1
    ReadOnly:                   false
    Size:                       1000203837440
    Symlinks:                   /dev/disk/by-id/scsi-35000000000000001-part1
                                /dev/disk/by-id/scsi-SASMT_2115_56A01000000000000403-part1
                                /dev/disk/by-id/wwn-0x5000000000000001-part1
                                /dev/disk/by-label/Backup4
                                /dev/disk/by-path/pci-0000:00:14.0-scsi-0:0:0:0-part1
                                /dev/disk/by-path/pci-0000:00:14.0-usb-0:5:1.0-scsi-0:0:0:0-part1
                                /dev/disk/by-uuid/f97bddeb-bf6b-41ca-aee7-87e0e9a63e17
  org.freedesktop.UDisks2.Filesystem:
    MountPoints:        
  org.freedesktop.UDisks2.Partition:
    Flags:              0
    IsContained:        false
    IsContainer:        false
    Name:               
    Number:             1
    Offset:             1048576
    Size:               1000203837440
    Table:              '/org/freedesktop/UDisks2/block_devices/sdb'
    Type:               0x83
    UUID:               0e6460e3-01