Welcome to Fractal Forums

hi there

if the default audio file is not found, setting of a new audio file in the uniforms window does not work, it says "file not found" but for the one already selected

Thanks for the report. I'll try to fix it before next release (at the end of the month).

Well, I cannot reproduce the problem. It works for me. When I set:
, launch the shader and then press play (in Uniform Controls View), I get file not found error (as you).
But when I choose some audio file later through Uniform Controls View and then I press play, everything works as expected.