KBA91004: AV Defender endpoint agent unable to connect

AV Defender uses an endpoint agent (epag.exe) module which may experience issues on 64-bit systems when the .NET Framework creates an incorrect value in the Windows Registry. In this situation, the following error message may be generated:

*** ERROR *** Failed to InitConnection. Error: Exception from HRESULT: 0x80040202

You can confirm that the managed device is experiencing this problem by performing the following:

  1. Create a .BAT file that contains the following command:

    REG QUERY "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework" /v Enable64Bit

  2. Upload the .BAT file to N-able N-central and run it on the managed device from N-able N-central. For more information, see Adding Scripting Tasks.
  3. If the device is experiencing this issue, the script will return the following result:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework

    Enable64Bit REG_SZ 1

  4. The problem is indicated by the returned phrase REG_SZ. The problem is not present on the managed device if the returned phrase is REG_DWORD as demonstrated by the following:

    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework

    Enable64Bit REG_DWORD 0x1

To correct this:

  1. On the managed device, run the command REG.EXE ADD HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework /v Enable64Bit /t REG_DWORD /d 0x1 /f

    This can also be performed by running the command on the managed device as a .BAT file from N-able N-central as described above.

  2. Re-start the device.