Hans, using latest from yesterday, I get the following error: tex error > tex error on line 22 in file cont-yes.mkiv: Valid keyword expected, likely 'minus' <lua output> mt xrunjit <to be read again> \relax <macro> \buff_verbatim_type_buffer_indeed ...rrentregime }tab{\typingparameter \c!tab }method{\p_buff_option }escape{\typingparameter \c!escape }nature{display}\relax \dostoptagged \endofverbatimlines \dostoptagged \stoppacked \typingparameter \c!after [...] You started a keyword but it seems to be an invalid one. The first character(s) might give you a clue. You might want to quit unwanted lookahead with \relax. This comes from a book with > 300pp. It compiles perfectly fine with MkIV, so the typo might be in LMTX itself. I wonder whether it would be possible to add the invalid keyword (and related command) to the error message. This would mean something like: tex error > tex error on line 22 in file cont-yes.mkiv: Valid keyword expected, got "invalid one" (related to "command"). This would help a lot to figure out where to start searching for clues for a MWE. Many thanks for your help, Pablo -- http://www.ousia.tk