Problem installing Ubuntu 18.04 on MacBook Pro (8,3) Late 2011

Hello,

First, I would like to say Hi!, this is my first post.

Now my problem


I would like to install Ubuntu on my MacBook pro 2011 (8.3)

- Intel Core i7
- 16 GB Ram
- 1 TB HD (this is where I want to install Ubuntu - the disk has been partitioned so I have OSX High Sierra + an MS-DOS FAT partition for Ubuntu (400 GB)).
- 1 TB SSD

I followed this tutorial (http://www.applegazette.com/mac/how-...al-boot-macos/)

This is what I did:


I partitioned my HD disk (MS-DOS FAT), I disabled SIP, I installed refind, I have Ubuntu 18.04 on a USB key.

The problem:

At the time of installation I get this error:


MODSIGN: Could not get UEFI db list

I'm a complete noob when it comes to Linux, but I want to learn.


Can you help me ?


Thank you in advance,


Tom