on my laptop I have installed OpenSuse 42.2, Linux Mint 18 and Windows 8. After installing the recommended updates for OpenSuse I can not boot Mint anymore. The following error message is displayed:
Error: /boot/vmlinuz-4.4.0-21-generic has invalid signature
Error: You have to load kernel first
OpenSuse works fine and also Windows can still be started - which is only a sore solace.
I had the same problem when I have installed Leap. Yet at that time I have afterwards also freshly installed the new version of Mint which replaced Leap’s boot menue with Mint’s with which I could start each OS. But now after the update Leap’s boot menue is in use again yielding the old problem.
I would be glad if someone could help me making Mint start again - preferably without having re-install it!
I have also requested help in the Linux Mint forum because I don’t know in whose area this problem falls.
Great info for those using dual-boot…or tri-boot in your case lol…yea, the Mint community is usually very helpful and quick to respond. One of the many reasons I’ve enjoyed Mint and openSUSE, is because of the communities for both. Glad you got your answer sir, good luck!
If they are using os-prober, it simply parses and extracts entries from bootloader configuration. No bootloader - no configuration (or even worse - they will find stale configuration frozen at the moment you change to no bootloader with yast; kernel installation and removal after this moment won’t be reflected).
So for now you need to make sure each bootloader is installed in different locations. root partition suits just fine. Problem in this thread sounds like both installed OS were configured to place bootloader in the same location (probably MBR).