Thanks for your feedback Louis.
I managed to get it working, (kind of, as it seems that I don’t have the proper remote/ir receiver), but here is what I did.
I am using the latest branch for Aurora/Teensy 3.6:
https://github.com/pixelmatix/aurora/tree/sm3.1-teensy3.6-64x64
Using the latest version of aJson:
https://github.com/interactive-matter/aJson
I also tried a prior version that was supposed to fix some compilation issues as indicated here, but I was getting the same errors.
At the end I edited aJson library following this reference:
https://gitlab.com/xarduino/lightsw/blob/master/patch/ajson-void-flush.patch, and this finally let me compiled the code for Teensy 3.6 
btw, I also edited the Aurora.ino because I don’t have the audio adapter (link), and changed some references:
From: #include <GifDecoder.h>
To: #include “GifDecoder.h”
And on Animations.h:
From: #include <FilenameFunctions.h>
To: #include “FilenameFunctions.h”