BrowserPane.Control is throwing an exception in .Net8 Addin

[esalvaJSAU5]

I created a custom addin project, This addin has a Test button in the ribbon.

The button click event will add a new BrowserPane to the active document. Im using AddByManifest to load the un managed active x control. 

During the execution of AddByManifest() the temporary MessageBox in the FormLoad event will shown, which makes me think that the control is loaded properly.

But when i try to access the BrowsePane.Control property, It is throwing an exception.

Does anyone have an idea on how to fix this problem ? 

I attached the CustomAddin that i created.

Thank you

[Michael.Navara · Accepted solution]

I looked into your code and I don't understand why you need to use BrowserPane when the requested content is derived from Windows.Forms.UserControl.

Isn't it better to use DockableWindow? C# sample is available for example here on my GitHub

Method BrowserPanes.AddByManifest is designed for placing ActiveX objects which is not your case in my opinion.

[esalvaJSAU5]

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[esalvaJSAU5]

Thanks for your reply. It works now. Thank you so much.