Ah okay, it’s green on my screen. Or maybe yellow for people with red-green-color-blindness.
Yes, I understand now. If you look at the video here: Projective Texture Mapping There it is okay. Did you try to do it like the guy in that video: ParallelProjection GeometryList - YouTube And it still did not work? Maybe your geometry is weird (use two flat boxes instead your concave double quad (or what that weird geometry is in your .gif files).
Might be that this plugin broke with recent changes. The code is from EARLY 2012. jME 3.0 is from LATE 2013. jME 3.1 is from LATE 2015. So maybe there was a breaking change in the core code or something like that.