When I process
\starttext
Hello, world!
\stoptext
I get the following error message:

/Users/bowen1/Library/TeXShop/Engines/LuaMetaTeX.engine:9: no such file or directory: /Users/bowen1/context-osx-64/tex/texmf-osx-64/bin/mtxrun

resolvers       | formats | executing runner 'run luametatex format': /Applications/LuaMetaTeX/tex/texmf-osx-64/bin/luametatex --jobname="Version" --fmt=/Applications/LuaMetaTeX/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luametatex/cont-en.fmt --lua=/Applications/LuaMetaTeX/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luametatex/cont-en.lui cont-yes.mkiv --c:autogenerate --c:currentrun=1 --c:file-line-error --c:fulljobname="./Version.tex" --c:input="./Version.tex" --c:kindofrun=1 --c:maxnofruns=9 --c:synctex="1" --c:texmfbinpath="/Applications/LuaMetaTeX/tex/texmf-osx-64/bin"
mtx-context     | fatal error: return code: 11

There is definitely a file 
/Users/bowen1/Library/TeXShop/Engines/LuaMetaTeX.engine.
Previous versions of lmtx process without any problem. 

Alan