Error message on startup


First of all, let me introduce myself. My Name is Oscar. Embedded software Engineer for TelematiQs B.V. from the Netherlands. We are currently building a device to interface with vehicles and communicate with the CAN bus. The project is going into the production phase and because of this I am asked to look into OpenTap for testing manufactured devices.

Now, I’m busy trying to figure out how everything works and planning on using Python to write some tests. I have already written some firmware on the device that can handle serial commands and run on device tests to test if all chips are routed correctly and so on. When tests are done, the results are written in a format over the serial connection.

In the process of trial and error I have reinstalled everything a couple of times. I now get the following error whenever i start the editor.exe or use the tap command in a shell:
10:20:46.148 Serializer XML Line 2: Unable to locate type ‘Keysight.OpenTap.Plugins.Python.PythonSettings’. Are you missing a plugin?
10:20:46.766 OpenTAP OpenTAP version ‘9.19.2+0e656415’ 64-bit initialized 10/19/2022 [1.04 s]
10:20:47.296 Main Latest version of ‘Visual Studio SDK CE’ is 1.4, your version is 1.2. Please consider updating. [529 ms]
10:20:47.296 Main Latest version of ‘SDK’ is 9.19, your version is 9.17. Please consider updating. [529 ms]
10:20:47.296 Main Latest version of ‘WPF Controls’ is 9.18, your version is 9.17. Please consider updating. [529 ms]

Does anyone have any clue what it is and how to fix it?

Kind regards,


1 Like

Hi @oscarkro, and welcome to the forum!

To me, it looks like you have had the Python plugin installed, then added some settings and afterwards deleted the plugin or maybe upgraded it to 3.0.

Which plugins do you have installed?


Thank you for your quick response! See the screenshot below for the complete list of installed packages. I believe I have everything? But like I said: I’m completely new to this whole Framework so correct me if I’m wrong.

Yes, everything looks good to me.

So the reason why you get the warning is that you previously had Python 2.x installed and that is not compatible with 3.0.

So it is not really a big problem. If you want, you can remove it by removing Python Settings.xml inside the Settings folder.

Thank you! It 's fixed now. I’m now going to look into developing it with C# as it seems the documentation and support is better! :slight_smile: I’m just looking into it and if it’s not easier, i’ll go back to Python!

1 Like

@oscarkro We are working to build out the Python documentation. The C# documentation has just existed for longer. I also want to point out that you should be able to use both C# and Python. You do not need to pick just one or the other.

In case you had not found it. There is fairly recently updated documentation for Python development here: