"System Validation" error in Font Book after generating from FontLab

I have a family of fonts I'm building in FontLab. They are all using the same exact kerning data and kerning classes. For some reason, one of the fonts is giving me a "serious error" in Font Book that says there is a "System Validation" error, with no further details.

I've tried taking a .vfb file from one of the working fonts, copying over glyphs from the font that's giving me trouble, and generating again. Same error. I think I've pinpointed the problem to be something kerning/class related, as if I copy/paste glyphs that AREN'T in a class and generate the font, I don't get an error in Font Book. But once I copy glyphs that are in a kerning class, I start getting the error.

I'm pulling my hair out because I have no idea why this is happening. I've tried resetting the metrics and kerning, then adding the data from the SAME .afm file the other fonts use, no luck. Same thing with the kerning class files. Any idea what could be causing this?! If I can provide you with anything else that might help solve this, just let me know. I'm beyond desperate at this point...

willryan42's picture

I'll paypal $15 to whoever can solve this problem!

jasonc's picture

I know this isn't what you want to hear, but I'd start looking outside FL to fix it. I don't suppose you have Metrics machine?
Or how about a simpler solution, have you tried TTXing the font and see if you still get the error?

I know, you'd rather know what the problem is, but..
Jason C

willryan42's picture

I've considered looking into other programs, but I think that would end up being next to impossible at this point. The family I'm working on is a layered family, where every font has the same metrics/kerning, classes, etc. Making one font in a different program is just begging for more issues to pop up...

I have no idea what TTXing is, but I'll look into it to see if it can help me out.

Té Rowan's picture

TTXing is, I believe, the use of the program 'ttx', a nifty bit of software written in Python that lets you view every table in a font.

Grzegorz Rolek's picture

You can get the OS X Font Tools from Apple's site at http://developer.apple.com/fonts/. It has a small utility that does the same series of tests as the Font Book validation, but generally gives much more verbose report. You'll also find some accompanying documentation with detailed instructions of how to use it.

jasonc's picture

Yeah, sorry, some jingo there.
I just meant, run the otf file through TTX, which converts it into an XML file with the .ttx extention, then just run it through TTX again to convert back to otf. The odds are slim this would help, but I've seen weirder things.

All things being equal, Grzegorz's suggestion is probably more helpful

willryan42's picture

Thanks guys. I've downloaded os x font tools and have started poking around the tutorial and info docs, not sure which part of it is used for testing fonts though...

And I've downloaded TTX, but I'm not sure how to install it. I keep seeing things saying that there is an easy installer for os x, but I just see a bunch of python files. Do I have to install and use in using terminal or is it a stand alone application?

EDIT: Nevermind, I figured out how TTX works and was able to convert my .otf to ttx and then back to .otf. Still doesn't validate... I'm still trying to figure out how to test fonts with os x font tools.

EDIT2: Alrighty, figured out os x font tools' validator using the "ftxvalidator" command. Either this isn't ouputting any useful information or I'm doing something wrong. These just look like parts of an .xml or plist file... not sure how helpful they are. Screenshot below.

Grzegorz Rolek's picture

Running ftxvalidator with just a filename gives you a report summary, nothing more. Run ftxvalidator -T /path/to/font for a detailed, tabular report. See also ftxvalidator -h (help) for all options available.

johnych's picture

I can try to help to solve this issue if you send me the problem font both in vfb and otf formats.


willryan42's picture

That'd be great johnych. You can email me at hello@willryan.us and I can send you the files and you can take a look.

johnych's picture


willryan42's picture

Hey guys

Malcolm Wooden was able to help me out with this one. Seems like the probably was related to how complex the font was, and me generating it with hinting enabled. Thanks again Malcolm!

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