The code below works with context2016.02.15, but fails with context2016.05.19.

Itemize within the defined paragraph (Mypar) no longer puts the thinrule in the margin (see the third question.) The \ansblank command seems to the second part of Mypar is 
the margin?  Pdf of the success and fail attached.

Thanks! John


\defineparagraphs[Mypar][n=2]
 \setupparagraphs[Mypar][1][width=0.5\textwidth] 

% label subquestions (a, b, c, etc) with answerblanks
\defineconversionset[myitemize][n,a][n]

% define the answerblank in right margin
\define\ansblank
  {\inright{\simplealignedbox{2em}{flushleft}{\convertedcounter[itemgroup:itemize][numberconversionset=myitemize,numberstopper=.]}\thinrule}\ignorespaces}

% \define\noblank
\define\noblank
  {\inright{~}}

% put them together to toggle printing of the answerblank
\define\blankon{\setupitemgroup [itemize] [style=bold,command=\ansblank]}
\define\blankoff{\setupitemgroup [itemize] [style=bold,command=\noblank]}

\starttext
\showframe
\startitemize[n]
\blankon
\item First question.
\blankoff
\item Second question has two parts.
  \startitemize[a]
  \blankon
  \item subquestion a
  \item subquestion b
  \stopitemize
\blankon
\startMypar
\item Third question refers to graphic at right. 
\Mypar
<A graphic/MPcode goes herer>
\stopMypar
\item Final question.
\stopitemize
\stoptext