AddInContent Build Action Causes Project to Become Miscellaneous File

[ManalSiddiqui]

So I am trying to re-create my project within Microsoft Visual Studio 2019 for ArcGIS Pro 2.8 project as my Add In does not work in 2.8 because the target framework is orginally for 2.9. I just created a new project and added all of the code/toolboxes/images needed for the project. The only thing is I need to set the Build Action for the Add-In Buttons to be 'AddInContent' from the default 'Compile'.  Like so :

However while doing so, the Project Name which is originally SkyWatch turns into Miscellaneous File like this and in doing that the buttons do not launch within Pro .

Any of the online forums suggestions do not fix this. If anyone has an idea of why this may be happening please let me know!

Thanks in advance.

[Wolf]

I think you misunderstood, only the button images (*.png files usually located in the images/darkimages folders) need to be set to build action "AddinContent", not the class files (*.cs) those need to be compiled.