Dear Michael and Otared, After updating ConTeXt to the latest version(2013.01.02.) and run the sample code.
\starttext $\hbar$ \stoptext
But I also got empty page. If I add either \setupbodyfont[xits] or \enablemode[lmmath], \hbar appeared. I also use Mac OSX mountain lion 64bit, luatex beta 0.74. In the log file, I found the message "Missing character:…" %%%%%%%%% … fonts > typescripts > unknown: library 'loc' (/Users/graph/ConTeXt/tex/texmf-context/tex/context/base/type-imp-texgyre.mkiv){/Users/graph/ConTeXt/tex/texmf-context/fonts/map/pdftex/context/mkiv-base.map} … … Missing character: There is no ħ (U+0127) in font texgyretermesmath-regular! backend > xmp > using file '/Users/graph/ConTeXt/tex/texmf-context/tex/context/base/lpdf-pdx.xml' … %%%%%%%%% I think that Otared doesn't have this kind of message. Do you have any idea to fix this? Thank you. Best regards, Dalyoung