It’s a weird error message, but the source seems to be this, in the code component:
mySound = new sound.Sound("InC.wav");
This seems to be a problem with creating sound objects through code components in Pavlovia: Is it possible to play continuous sound in Builder?
I would say your best bet is probably to create the sound component itself in the builder, but control its playback through a code component, since you seem to only want to have the sound play on the first cycle of your trial loop.
On that note, that conditional is probably going to break as well, for unrelated reasons. You want to replace “fam_aud.thisN” with “trials.thisTrialN”. See here: "Take a break" works locally but not online