Hi! Right, PD4ML redirects System.err, but only during particular single actions: by an internal AWT image creation and by parsing SVG and mathML – to suppress non-switchable warnings to avoid log file flooding.

A redirecting of System.err is not a perfect idea as it impacts the entire JVM for very short time, but since we added the redirect long time ago there we no problem reports from our customers.

It can be disabled by -Dpd4ml.enable.stderr.redirects=false command line parameter, passed to JVM