Dear all, My last question concerning feature files has been resolved, my feature files now work fine. But there is one problem that still remains. The standard ligatures in the font I use (Andron Mega Corpus) work fine when approached by name in the feature file (some of them are in the PUA here); However, other ligatures, notably Th, do not work in stable nor beta. When I run context mkiv and it calls on e.g. the Th ligature, i get "!LuaTeX error (file:(...)): Invalid glyph index (gid ...). I tested it on palatino linotype which does the same. Interestingly, the gid that luatex says is invalid is always the one after the last glyph in the font (For palatino linotype, 1328; for Andron Mega Corpus, 5486). In Andron Mega Corpus, I furthermore tested all the ligatures that had a unicode codepoint (PUA) and they all work when referenced by name. All those that do not, however, fail to work. What is going on here? Working on Mac OS X 10.6.7, btw. Some help is greatly appreciated. Kind regards, Stef Schoonderwoerd