updated dual boot win10/leap 42.3 to win10/leap 15 beta (01 feb 2018)

during install it is reported that /dev/sda4 is not recognized as a block
device.

Device     Boot      Start        End   Sectors   Size Id Type
/dev/sda1             2048     718847    716800   350M  7 HPFS/NTFS/exFAT
/dev/sda2           718848  982804427 982085580 468.3G  7 HPFS/NTFS/exFAT
/dev/sda3  *     982804480 1951815679 969011200 462.1G  f W95 Ext'd (LBA)
/dev/sda5        982806528  987000831   4194304     2G 82 Linux swap / Solaris
/dev/sda6       1070895104 1071937535   1042432   509M 83 Linux
/dev/sda7       1071939584 1155844095  83904512    40G 83 Linux


I found that the default boot selection was not saved after zypper dup 42.3 -->
15.0 so started yast2 bootloader and gave same error.


Error                                                                          
  Internal error. Please report a bug report with logs.                         
Run save_y2logs to get complete logs.                                           
Details: unknown device /dev/sda4
Caller:  /usr/share/YaST2/modules/BootStorage.rb:136:in
stage1_devices_for_name'