Hi @rod_amaral!
Note that audioinjector uses some GPIO pins that are already used by Zynthian default configuration (the last statement is incorrect and amended in another comment below …). Althought you have no rotary encoders in your setup, Zynthian UI will try to read from it. I’ve fixed this in the last software version, so you should try it:
When you have correctly updated the UI software, you should edit the config file “zynthian_gui_config.py” and configure the GPIO layout as “dummies”:
hw_version="DUMMIES"
This will prevent the zyncoder library to try to configure and read the rotary encoders & switches.
Kind Regards!