Winforms Designer Toolbox is empty except for material elements

I'm making a WinFormsApp in visual studio with C# and .NET Framework 6.0. I also have the NuGet package MaterialSkin.2, and I am using that skin to make the form. I tried to add an imageList to the design of the form, but I realized that there were no elements other than the material ones, As seen in this image. I tried resetting the toolbox, but it didn't work. I right clicked the toolbox and enabled show all, but imageList (And all the other winforms elements I should have been able to use) were greyed out and I could not drag them onto the designer.