This is the error when installing the latest beta:

! Undefined control sequence.

system          > tex > error on line 808 in file /Users/hans/TeX/context-new/tex/texmf-context/tex/context/base/context.mkiv: Undefined control sequence ...


<argument> \??bj 

\setsomevalue #1#2->\expandafter \def \csname #1
                                               #2\endcsname 
\p!doassign ...fter \setsomevalue \fi \fi {#1}{#2}
                                                 {#3}
\xprocesscommaitem ...@relax@ #1==\empty \@relax@ 
                                                 \doubleexpandafter \xproce...
<argument> \c!n =3, \c!width 
                            =1em, \c!height =1ex, \c!depth =\!!zeropoint , ...
\xdogetparameters #1]->\xprocesscommaitem #1
                                           ,],\@relax@ 
l.808    \c!color=]


Is it possible the error is in file typo-mar.mkiv? There I find a macro call   
  \usemargindatastyleandcolor\c!style\c!color
but searching the sourcesfor its definition does not reveal it.
Could it be forgotten?

Hans van der Meer