Strange. It looks okay. Is this the only feature?

First of all: never thought that my newbie questions will be answered by Mark Simonson HIMSELF!!! Big fan of your work, really...

as for the stylistic set errors - weird thing...I rewrote them, because I was fraid of accidental Cyrillic characters in the feature definition. Everything is fine until I add

sub eight by eight.ss01;

after I add this one, FL says the same again

ERROR: There was a problem while compiling OpenType font. Final .otf font is not saved. Please, check OpenType features definition for errors.

It also occurs when I add

sub nine by nine.ss01;

but not with

sub zero by zero.ss01;

Weird, huh?

Gee whiz, I never thought I would be famous in Bulgaria... :-)

Anyway, I'm still stumped.

It seems odd that the error is only triggered when you add the lines for eight or nine. If it were a problem with missing glyphs or glyph names, the error would be different ("missing glyph" error). If it were a problem with Cyrillic characters creeping in, again it would be a different error ("invalid character" error). Instead, you just get this maddenly vague error ("there's a problem") which offers no clues.

Have you tried contacting FontLab support? They may be willing to look at the font and tell you what's wrong.

I got that same error message when I tried to substantially change the kerning in an existing Adobe font -- both class & exceptions. FL didn't complain when the *features* were compiled (and yes, I made the changes in the features file, not the metrics window), but did when I tried to generate the .otf.

I never solved it; I assumed I'd just done something to throw it into a loop.

You might try renaming the alternate characters

zero.alt
one.alt
two.alt
three.alt
. . .
nine.alt

Then use your stylistic set feature with the replacement names suitably changed. It shouldn't help, but would be easy to do.

I guess I'd also go back & make sure the regular numbers were all OK. Then if it still didn't work, give it to FontLab & see if they'll debug it.

One thing worth trying if you go at it yourself is to limit things. Start a *new* font, and put in it only the regular numbers & the alternative numbers. See if it will compile. The add the ss01 feature & try again. If that works, there is something else in you *old* font getting in the way.

Ivan,

Just for the hell of it, I made up a little test font. It had only a space character and the numbers 0-9 (from some Stencil font). I added the numbers 0-9 from Sistina, named them *zero.ss01* etc., & no Unicode index. Wrote a feature -- wrote it out longhand just like you did -- compiled the features & made a font. Everything worked fine.

Opened up ID-CS2, set the numbers twice, applied the stylistic set to the second row of numbers -- they changed. It even printed out.

I'd say that whatever is going wrong for you isn't specifically your feature, but some inadvertent conflict with something else.

Sorry I'm no help, & good luck