Datasmith Will Not Let Me Import .C4D files when Unreal Engine is build from source

I have two versions of Unreal 4.25.3 installed on my computer; one installed from the Epic Games Launcher, and one that I built from source (release 4.25.3) (Windows 10, following the instructions here). In both versions, I went into the plugins section and enabled the following plugins.

Then I restarted the editor. When I click on the “Datasmith” icon (to the right of Settings and the left of Blueprints), this is what I options I have available in the the version that I built from source:

And these are the options I have available in the version I installed from the Epic Games launcher:

As you can see, the version of Unreal Engine that I built from source does not allow me to import .c4d files even though I have that plugin enabled. Why won’t it let me import .c4d files? Is there another part of the source project that I need to build? If so, can you please explain in detail how to do it? Thank you.