Similar questions have been posted here, but none of the proposed solutions had worked for me so far, so I decided to write it down here, looking for help.
I'm in a Lenovo T450 with windows 10 and ubuntu 16.04 previously working properly. Then, I made a fresh installation of Ubuntu 18.04 and what it finished the process, the computer did not boot at all. No booting options appeared, either. After showing the manufacturer logo, the message
System BootOrder not found. Initializing defaults. Reset System shows up every ~4 seconds.
I tried repairing the boot system by running
boot-repair, but it hasn't worked. The final message of this process gives the following URL:
http//paste.ubuntu.com/p/kQjxF3wmZR/, to be used in case of problems, I think.
Also: I was able to go to the Startup Menu to try see if I could edit the startup configuration through the BIOS setup utility. I tried following instructions from here, but not all the options they mention appear in my case, so I did have no success.
I found also suggestions related to a similar problem but on a Acer Aspire ES1-533, which I'm trying to understand, but not sure if they'd work, considering the different system.
Could you please give a hint on how to solve this issue? Thanks.