In the latest beta, processing
\starttext

Hello world!

\stoptext

 produces many lines of

Synchronize ERROR: unknown node type 12


between the lines

fonts           > 'fallback modern-designsize rm 12pt' is loaded

 and

backend         > xmp > using file '/Applications/ConTeXt/tex/texmf-context/tex/context/base/lpdf-pdx.xml'


Alan