Hello,
Often Firewall Defender blocks access, causes errors, so you can first check recently blocked!
Just in case check if you register correctly, in the right test channel.
https://learn.microsoft.com/pl-pl/windows-insider/flight-hub/
Other options:
Download the ISO file from Microsoft's official website and double click on it and run it as administrator This will repair your Windows and fix any corrupted files. After the update, leave your PC on Windows update and make sure you install every driver.
https://www.microsoft.com/en-us/software-download/windows10
You can allways roll back to Windows 10.
First, create a Windows installation drive:
Go to the Windows 10 ISO download website on another PC.
Click on Download tool now.
Insert a blank USB drive with at least 4 to 8 GB of space in it.
Run the tool and select Create an installation medium for another PC. Select the correct USB drive.
Let the process finish.
Backup all your data:
Attach the USB to the affected PC and boot from it. (On computer startup, hold down Esc, Del, F12 or F10 key)
In the Windows installation environment, select your language and click next.
Click Repair this PC.
Click on Troubleshoot>Advanced Options>Command Prompt.
In the cmd, type notepad.exe and hit enter.
In the notepad window, click on File>Open. This will open a file dialog.
Using the file dialog, copy all your data to any other partition or drive.
Close the notepad.
When your data is backed up, install Windows 10 using the USB.
Exit the advanced menu and click on Install now.
When prompted, select Custom install and select the current Windows drive.
Ignore any warnings.
I hope this will help you!
Regards,