I installed openSUSE Tumbleweed on my HP probook in dual boot with Windows 10. Then, I noticed some bugs in openSUSE and decided to try Ubuntu 18.04. But after I installed Ubuntu the openSUSE didn't show up in the boot options any more.
I searched for help and found out that I should run some sudo grub-something (don't remember what) and the grub.cfg was rebuilt and then openSUSE started appearing in the GRUB menu on boot. But when I choose openSUSE in that menu I get an error saying
cannot find vmlinuz-5.1.4... Need to load kernel first
I tried searching everywhere but have no luck, so I'm here to get a little help. If you need more details, please, let me know.
EDIT:
I don't know if openSUSE is sharing /boot with Ubuntu.
This is the output of lsblk -o name,fstype,size,label,mountpoint
NAME FSTYPE SIZE LABEL MOUNTPOINT
loop0 squashfs 140,7M /snap/gnome-3-26-1604/74
loop1 squashfs 13M /snap/gnome-characters/139
loop2 squashfs 14,5M /snap/gnome-logs/45
loop3 squashfs 8,4M /snap/canonical-livepatch/77
loop4 squashfs 34,6M /snap/gtk-common-themes/818
loop5 squashfs 2,3M /snap/gnome-calculator/260
loop6 squashfs 91M /snap/core/6350
loop7 squashfs 3,7M /snap/gnome-system-monitor/57
sda 298,1G
├─sda1 ntfs 500M
├─sda2 ntfs 242,1G
├─sda3 1K
├─sda4 btrfs 35G
├─sda5 swap 3,8G
└─sda6 ext4 16,2G /
sr0 1024M
