How to Stop Receiving Insider Builds for Windows 10 without breaking VHD setup: \windows\systems32\winload.efi (0xc0000428)

I have enrolled myself into Dev Channel of Windows Insider Program. I am not quite sure whether I needed to enroll myself to Dev Channel of Windows Insider Program to setup my machine as a dual boot, but here is my dual boot setup:

1. Windows 10 (Version 10.0.21286.1000) [VHD]
   -> Installed: Windows10_InsiderPreview_Client_x64_ja-jp_21286.iso
2. Windows 10 (Version 10.0.18363.1440)

I say I am not quite sure, because I believe I could have download the ISO of Dev Channel build from Windows Insider Preview Downloads's Select edition without enrolling and probably installed it without a hitch maybe.

Now, I want to terminate receiving of Dev Channel's builds by following the instruction in stop receiving Insider Preview builds on my main Windows 10 (Version 10.0.18363.1440). If I were to receive them, then it should be on the other one. When I stop it though, I get the following error message while booting my machine. Luckily I can load Windows 10 (Version 10.0.18363.1440) but the other one will result in an endless loop of Screenshot 1 & Screenshot 2. In order to get out of the endless loop, I loaded the Windows 10 (Version 10.0.18363.1440) and restarted receiving of Dev Channel's future builds.

1. Screenshot 1: Preparing Automatic Repair
2. Screenshot 2: \windows\systems32\winload.efi (0xc0000428) "The digital signature for this file couldn't be verified."
3. Screenshot 3: Selection of Windows
4. Screenshot 4: Loading of Windows 10 (Version 10.0.18363.1440)

Do you have two separate Windows 10 Licenses for the two installs? ... Answer: No

Two installations of the same Windows License (OEM or Retail) on the same computer may be allowed. However my experience here is that I have had issues a while back when trying to run two systems simultaneously under one license.

More importantly:

You are also using Windows 10 V1903 (build 18363) and trying to use a version of Windows Insider that is not completely current.

Now, I want to stop receiving Dev Channel's Insider Preview Builds on my main Windows 10 (Version 10.0.18363.1440).

In a stable situation (one installation) you can exit (quit) the program and your machine will return to Production at the first opportunity.

In this situation, Microsoft has said that to exit the Insider program and return to Production "right away" you must back up and reinstall Windows. Microsoft has also said that if Windows is not working, it may be necessary to reinstall.

Because your system is not working properly, I suggest you must do that here as well: Back up everything, remove the dual boot, and install Windows fresh. Also come up to the current version.