Stop error 7E on a server running NFS in Windows Server

Applies to: Windows Server 2019Windows Server 2016

Symptoms


A Windows Server 2016-based server that runs the Network File System (NFS) service experiences a Stop error (also known as a bugcheck or blue screen error). The error code is 7E, and the service that originated the error is Nfssvr.sys.

Resolution


Important
Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.

To fix this problem, the July 14, 2020 KB 4565511 (build 14393.3808) includes an update to Nfssvr.sys. Make sure that this update is installed.

To enable the fix

On computers that run Windows Server 2019, the fix is enabled automatically. No further action is necessary.

On computers that run Windows Server 2016, the fix is disabled by default. To enable the fix, you have to set a registry entry in addition to installing the binaries. (Windows Server 2019 does not require a registry key change.)

In Windows Server 2016, you can make this change by using the command line, as follows.

  1. On the computer on which you have installed the update, open an administrative Command Prompt window.
  2. Run the following command:
    reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NfsServer\KBSwitch /v 769E60B7-C2FF-41B0-AD1F-14FC26F6F46B /t REG_DWORD /d 1 /f


To disable the fix

In either Windows Server 2019 or Windows Server 2016, you can disable the fix by using either of the following methods:

  • Start Registry Editor, locate the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NfsServer\KBSwitch\769E60B7-C2FF-41B0-AD1F-14FC26F6F46B entry, and then change the value to 0
  • Delete the registry entry. To do this, open an administrative Command Prompt window, and then run the following command:
    reg delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NfsServer\KBSwitch /v 769E60B7-C2FF-41B0-AD1F-14FC26F6F46B /f