What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

How do I solve a .NET Framework error PE104 or PE087?



For my sensors on the probe of my core server, on one or more cluster nodes, or on a remote probe, I get the following error message:

This sensor requires the .NET Framework version 2.0 or higher (code: PE104)


This sensor requires the .NET Framework version 3.0 or higher (code: PE104)


External EXE/Script did not return a response (code: PE087)

-net error framework paessler-tools-family pe-code ptf

Created on Feb 9, 2011 10:41:38 AM by  Daniel Zobel [Product Manager]

Last change on Feb 16, 2011 5:38:17 AM by  Daniel Zobel [Product Manager]

2 Replies

Accepted Answer



The sensor you have installed requires the Microsoft .NET framework to be installed on the system running the PRTG probe, either on every cluster node, or on the computer running the remote probe (depending on where you set up the sensor).

In order to run the sensor, please install .NET on all systems running a PRTG probe. Usually, you will need .NET version 2.0, 3.0, or 4.0. They come with Windows Update (or google for ".NET framework download").

Please note: You have to install versions 2.0 and 3.0 explicitly. Installing a higher version (e.g. 4.0) will not work! The exact .NET version which a sensor needs is given in the respective manual sections.

Created on Feb 9, 2011 10:43:58 AM by  Daniel Zobel [Product Manager]

Last change on May 8, 2014 3:52:14 PM by  Gerald Schoch [Paessler Support]



I had the same problem. There was no error running from console, just blank line. Only PRTG reported PE087.

You can check what versions of .NET framework are installed with this VBScript (save as net.vbs file and run on server)

Dim Act :Set Act = CreateObject("Wscript.Shell")
Dim Obj, Rg1, Rst

Dim Reg :Reg = Array( _
  "1 - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\1.0.3705\Version", _
  "1.1 - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\1.1.4322\Version", _
  "2 - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727\Version", _
  "3 - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Version", _
  "3.5 - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.5\Version", _
  "4 Client Profile - HKEY_LOCAL_MACHINE\Software\Microsoft\NET Framework Setup\NDP\v4\Client\Version", _
  "4 Full - HKEY_LOCAL_MACHINE\Software\Microsoft\NET Framework Setup\NDP\v4\Full\Version")
On Error Resume Next 
    For Each Obj In Reg
     Rg1 = Split(Obj," - ")
     If IsNull(Act.RegRead(Rg1(1))) Then
      Rst = Rst &  "Missing Net Frame Work : " & Rg1(0) & vbCrLf 
      Rst = Rst &  "Confirm Net Frame Work : " & Rg1(0) & " - " & Act.RegRead(Rg1(1)) & vbCrLf 
     End If

    MsgBox Rst, 4128,"Net Framework Info"

Created on Mar 21, 2012 3:35:07 PM

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.