Re: [NTG-context] LuaTeX error ... object in use

There is no test file, and I still do not know which font you are using. Attempting to find the problem is closer to tea-gazing than to debugging at the moment. Font features cannot be debugged independent of the actual font.

Thanks, I understand. I had been using GaramondPremrPro (which has all four features and worked with 0.50). You gave me the idea to try GillSansMTPro, which also has the four features. I got a very interesting result---for it, numr and dnom work, but sinf and sups do not. I don't know how I could prepare a test file for you short of sending you my fonts and typescripts (which I'd be willing to do).