WSL2: The remote procedure call failed.

[jasonyux]

Environment

Windows build number: 10.0.20211.0
Your Distribution version: 20.04
Whether the issue is on WSL 2 and/or WSL 1: WSL 2

Steps to reproduce

WSL logs: https://aka.ms/AA9nw6h

Expected behavior

Ubuntu20.04 starts.

Actual behavior

Ubuntu20.04 fails to launch with an error:

The remote procedure call failed. 
[process exited with code 4294967295]

with:

PS C:\Users\26238> wsl -l --verbose
  NAME                   STATE           VERSION
* docker-desktop-test    Stopped         2
  Ubuntu-20.04           Stopped         2

Solutions Tried

1. I have reduced the length of my path variable to 1324, and I think the remaining ones are important hence further cutting it down would not be worth it (WSL2-Error: A connection attempt failed on Windows 19555.1001 #4860).
2. I have also uninstalled the update KB4571756, which does not solve the problem (though the problem did happen the next day after I updated my windows on 9/13 with KB4571756, yet uninstalling it still doesn't work) ("Element not found" after install KB4571756  #5880).

[adrianvaneeden]

Microsoft has acknowledged that this is an error in KB4571756. See workaround on this thread in response by @alexpaluzzi.

[jasonyux]

Microsoft has acknowledged that this is an error in KB4571756. See workaround on this thread in response by @alexpaluzzi.

I have referred to the solution in the Solutions Tried section. In short, uninstalling the update did not fix the issue for me.

[sjansen1]

For me after installing that update it not just break WSL2, it breaks Hyper-V in generell on 2004 and 20H1. Other stuff that use Virtualization like Device Guard still works.

[jasonyux]

For me after installing that update it not just break WSL2, it breaks Hyper-V in generell on 2004 and 20H1. Other stuff that use Virtualization like Device Guard still works.

OMG. Were you able to fix it? I feel like my Hyper-V is probably broken as well.

[onomatopellan]

If you are in build 20211 you didn't need KB4571756. Did you install it manually?

[sjansen1]

For me after installing that update it not just break WSL2, it breaks Hyper-V in generell on 2004 and 20H1. Other stuff that use Virtualization like Device Guard still works.

OMG. Were you able to fix it? I feel like my Hyper-V is probably broken as well.

I fixed it by using this workaround by restoring and registering VmSynthNic.dll see #5880 (comment)

[jasonyux]

If you are in build 20211 you didn't need KB4571756. Did you install it manually?

No, this is the version I got from ver command after uninstalling the KB4571756 and rebooting.

[mcornella]

Duplicate of #5907.

[jasonyux]

Duplicate of #5907.

I am trying that solution now. But somehow my permission to overwrite that file got denied, it says I can only modify the files in System32 if I am a TrustedInstaller. Trying to overwrite the file with administrator permission did not work either.

[jasonyux]

For me after installing that update it not just break WSL2, it breaks Hyper-V in generell on 2004 and 20H1. Other stuff that use Virtualization like Device Guard still works.

OMG. Were you able to fix it? I feel like my Hyper-V is probably broken as well.

I fixed it by using this workaround by restoring and registering VmSynthNic.dll see #5880 (comment)

Thanks, I am trying that now. But to override the file in System32, it says I need to be a TrustedInstaller. Using administrator permission did not work. How did you do it?

[jasonyux]

Duplicate of #5907.

For me after installing that update it not just break WSL2, it breaks Hyper-V in generell on 2004 and 20H1. Other stuff that use Virtualization like Device Guard still works.

OMG. Were you able to fix it? I feel like my Hyper-V is probably broken as well.

I fixed it by using this workaround by restoring and registering VmSynthNic.dll see #5880 (comment)

NVM. That file is not missing and the last modified date is 09/06. The backup file I found has the same size and last modified date. So I guess replacing that file will not help.

[onomatopellan]

@jasonyux You say you uninstalled KB4571756. Can you open View Reliability History and see which day the KB4571756 was installed? Also which build number do you see in winver.exe right now?

[jasonyux]

@onomatopellan

1. Under the View Update History page, I see the update Windows 10 Insider Preview 20211.1000 (rs_prerelease) installed on 9/13. Clicking on the uninstall upgrade option, the latest update with Microsoft is KB2565063 (I think because I have already uninstalled the KB4571756), which is installed on 6/28.
2. The build number I see with winver is 20211.1000

[onomatopellan]

@jasonyux Thanks. I know this can be confusing but when you upgrade to an Insider Dev build like 20211 you are in a new state where cumulative Updates like KB4571756 doesn't apply.
Since you are now in build 20211 and you still see "The remote procedure call failed" then your issue is now a duplicate of #5907 and you should post the logs there too.

Your only option is rolling back to the Windows version you were before upgrading ( build 19041?) with Settings ->Update & Security -> Recovery. After that you should be able to use the available workarounds.

[jasonyux]

@onomatopellan Thanks. Will try it now.

[jasonyux]

@onomatopellan Recovering my version to the previous update via Settings ->Update & Security -> Recovery fixed my issue. Now Ubuntu20.04 can be launched successfully (now I am 20206.1000). Thank you.

[jasonyux]

Duplicate of #5907

[SylvioLe]

For me after installing that update it not just break WSL2, it breaks Hyper-V in generell on 2004 and 20H1. Other stuff that use Virtualization like Device Guard still works.

OMG. Were you able to fix it? I feel like my Hyper-V is probably broken as well.

I fixed it by using this workaround by restoring and registering VmSynthNic.dll see #5880 (comment)

Thanks, I am trying that now. But to override the file in System32, it says I need to be a TrustedInstaller. Using administrator permission did not work. How did you do it?

to get trustedinstall you need to modify the services command line to do your work. you can do that by using the very old and often unknown tool called sc.exe with the config parameter. but disable any anti-maleware-software to avoid service hooking false alarms.
first step modify service with sc second step netsh service start...you can do that to perform every action the admin status you wont let.