Hello. ardour2 included non-free code. File List: "ardour-2.8.16/libs/pbd/dmalloc.c" This code license is not allow commercial use. It is non-free. Thanks. Reference: https://bugs.debian.org/cgi-bin/bugreport.cgi?archive=no&bug=810754
Fixed in ardour2-2.8.16-21.fc24 (and fc25).