I am finding that the latest beta fails when asked to set ancient Greek using Thomas’ module and the MKII engine. The error message reads:

! Missing \endcsname inserted.
<to be read again> 
                   \@@laagrpatterns 
\dodosetnormallanguage ...fcsname \??la \??la #1#2
                                                  \endcsname \edef \thenorma...

\dosetnormallanguage ...ding :\currentmapping :}#1
                                                  {\dodosetnormallanguage {:...

\setnormallanguage ...efalse \synchronizepatterns 
                                                  \ifdone \else \def \synchr...

\docomplexlanguage ...age \currentdefaultlanguage 
                                                  \the \everylanguage \enabl...

\complexlanguage ...edlanguage \docomplexlanguage 
                                                  \fi \else \showmessage \m!...
...
l.78 ...et out the whole truth (\grk{>alhje'i[an]}
                                                  ) for us and demonstrated ...

? 

The file worked with earlier versions.

Alan