In case you never solved this: after compiling the latest AM from source this error no longer appears for me.
https://github.com/mickelson/attract/wiki/Compiling-on-the-Raspberry-Pi-%28Raspbian-Jessie%29There is a useful tip at the
bottom of the build instructions:
"Add the parameter "-j4" when you run make on a pi2 or pi3 to speed the build significantly."
This tip would probably be more useful at the
top of the instructions!
AM itself doesn't take long to compile on an RPi3. FFMPEG, on the other hand, takes about an hour if you don't use -j4... you know, because you didn't read that far down at the start

Caveat: Your layout may or may not be 100% compatible with AM 2.3.0, depending on how recent your layout is. Take a backup of your SD card first! I used an older (10 months or so) pre-built image and had to make a couple of modifications to the layout files after building the latest AM.