PopcornFX Plugin BETA

When I try to run UE4 with the PFX plugin, I get the following:

Running F:/atd/Engine/Binaries/DotNET/UnrealBuildTool.exe allthingsdie Development Win64 -project=“F:/atd/allthingsdie.uproject” -editorrecompile -progress -noubtmakefiles
WARNING: PopcornFX SDK not found, some build might fail
WARNING: PopcornFX SDK not found, some build might fail

Is this a known issue? I couldn’t find anything in troubleshooting or whatnot. This is preventing me from building the plugin successfully or getting into the editor.

Using a custom build of the engine based on 4.9.0 and using PopcornFX Plugin 0.5.5 with PopcornFX version 1.8.3.

I tried to comment out the “return true” that follows that warning and another line is displayed, but it never builds successfully.