Hello,
If I compile the file with context from texlive 2016, no problem. But with context from standalone, I get an error ("tex error on line 1 in file /home/fab/ntg53.tex: ! Missing } inserted")
thank you,
Fabrice

\defineframed
  [FRAME]
  [frame=off,
   offset=0pt,
   location=low,
   width=\struttotal,
   background=color,
   backgroundcolor=darkred,
   foregroundcolor=white,
   forgroundstyle=bold]

\defineprocessor[ACPROCESSOR][command=\FRAME]
\defineconversionset[ACCONVERSION][][ACPROCESSOR->n]

\startsetups[table:initialize]
\setupTABLE[start]
           [align={middle,lohi},width=0.12\textwidth,type=\tfx,offset=1ex]
\setupTABLE[column][first]
           [align={middle,right},width=0.52\textwidth]
\setupTABLE[1][1][frame=off]        
\stopsetups

\definelabel[TableRow][text=,numbercommand=\FRAME]

\starttext

\startmidaligned
\bTABLE[setups=table:initialize]
\bTR
    \bTD      \eTD
    \bTD   a  \eTD
    \bTD   b  \eTD
    \bTD   c  \eTD
    \bTD   d  \eTD
\eTR
\bTR
    \bTD \TableRow\ question \eTD
    \bTD \eTD
    \bTD \eTD
    \bTD \eTD
    \bTD \eTD
  \eTR
  \bTR
    \bTD \TableRow\ question \eTD
    \bTD \eTD
    \bTD \eTD
    \bTD \eTD
    \bTD \eTD
  \eTR
\eTABLE

\stoptext