In the following example, it is the &quot;;&quot; that leads to the error<br>\def\vect#1{%<br>  \overrightarrow{#1}<br>}<br>\starttext<br>$({\rm O};\vect{e_{x}})$ <br>\stoptext<br><br>If you suppress it, it works fine. (???)<br>
<br><div class="gmail_quote">2009/5/13 Aditya Mahajan <span dir="ltr">&lt;<a href="mailto:adityam@umich.edu">adityam@umich.edu</a>&gt;</span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="im">On Wed, 13 May 2009, Flavien Lambert wrote:<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Dear all, I didn&#39;t use ConTeXt for some time and, so, have just re-installed<br>
the minimals tonight. When running on some of my files, Mark II does its job<br>
well but Mark IV tells me<br>
<br>
error: Invalid field id nucleus for node type choice (0)<br>
.<br>
l.133 ... M décrit l&#39;axe $({\rm O};\vect{e_{x}})$<br>
                                                  avec une vitesse<br>
$\dot{x}...<br>
<br>
I have absolutely no idea what it is trying to say to me...<br>
If related, the macro is defined by<br>
\def\vect#1{%<br>
 \overrightarrow{#1}<br>
}<br>
</blockquote>
<br></div>
Can you create a minimum example. This runs fine here<div class="im"><br>
<br>
\def\vect#1{%<br>
  \overrightarrow{#1}}<br>
<br></div>
\starttext<br>
$\vect{e_{x}}$<br>
\stoptext<br>
<br>
Using ConTeXt  ver: 2009.05.12 22:35 MKIV<br><font color="#888888">
<br>
Aditya</font><br>___________________________________________________________________________________<br>
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___________________________________________________________________________________<br>
<br></blockquote></div><br><br clear="all"><br>-- <br>Flavien.<br>----------------------------<br>&quot;Quantum objects are completely crazy but, at least, they are all crazy in the same way.&quot; R.P. Feynman.<br>