[NTG-context] fontloader: “can't convert <float> into tounicode”

Hi, loading this font: https://collab.itc.virginia.edu/access/content/group/26a34146-33a6-48ce-001e... causes the fontloader to emit a dozen or so messages of the kind fonts > loading > can't convert 7.27550912993e+22 into tounicode fonts > loading > can't convert 3.1248073774797e+32 into tounicode fonts > loading > can't convert 4.731809353839e+27 into tounicode ... example code: \starttext foo {\definedfont[file:TibMachUni-1.901b.ttf*tibetan at 33pt]༡༢་༣༤་༥༦་༧༨} bar \stoptext is this harmless? The typeset result appears to be satisfying. Best regards, Philipp