disk utility – Triple boot Catalina 10.15.7, windows 10 (not bootcamp but NTFS), Unbuntu 20.10

I am using a 1 TB SSD with a macbook pro 2012 initially split into 2 x 500g: Catalina and Windows 10 NTFS (NON bootcamp partition). To install Unbuntu, I had to use the Catalina partition because the Windows partition would not allow me to partition it. So I end up having a 250G Catalina partition, a 250g Unbuntu partition along with a 500G Windows 10 partition.

Both, Catalina and Windows 10 (non bootcamp) partitions were running perfectly before the Unbuntu install. The Linux installs went very well. I have used David Anderson install process. Here is the link:

How can I triple boot MacOS Catalina , Ubuntu 18.04, and Windows 10

I did follow the step very carefully. The result was a fully working and fast Unbuntu partition. This thing shot down in less than 3 seconds and boot in less then 10. Anyway, I manage to install Refind which made all 3 partitions appear on startups. After booting Catalina and Unbuntu with success, the Windows partition fails to do so, showing instead this message:

** No bootable device, insert boot disk and press enter. **

This is usually called for a bootcamp partition problem but it seems the Unbuntu install, particularly the step where we use grub, and the step where we need to prevent hybrid disk use, may have or probably did broke something into Windows NTFS partition.

I am new to all this stuff so bear with me.

What I did next? I install the third party software gdisk and ran the thing into recovery mode. Here is a link of the procedure :

Bootcamp: no bootable device – insert boot disk and press any key

I followed the steps carefully hoping the hybrid state would fix the window partition and keep Catalina and Unbuntu running. It was a long shot I guess. The result was as expected: bad. Unbuntu is not showing up into the boot menu ; refind does not work anymore, and when I use the Mac option startup menu, Catalina and Windows hard disk do show up but Windows won’t boot. I get this message:

** Error loading operating system_**

No doubt the hybrid part seems to have broken both Windows and Unbuntu along with Refind. Nothing can be done from that message window except restarting the mac from the power button.

Once I boot into Catalina, the Windows 10 partition still shows up on the desktop. All files are there. The Unbuntu partition is still visible in disk utility partition view. It is located right between Catalina and Windows partition as you can see on the screenshot. By the way Windows partitin is the “OS” one.

disk utility partition view

Even when Unbuntu was booting perfectly, it did not show up anywhere except in disk utility partition view or on startup when Refind was still working before the gdisk process.

So, I guess the problem may come from the fact that Unbuntu was installed in second position because the NTFS Windows partition is non-partition-able.

Any idea to fix this?

Have a good one,

Luc