Hans, this is a standard eror message now: tex error > tex error on line 9 in file cont-yes.mkiv: Undefined control sequence <macro> \strc_sectioning_empty_correction \ifconditional \c_strc_sectioning_empty \penalty \plustenthousand \vskivskip -\lineheight \kern \zeropoint \prevdepth \strutdepth \fi <macro> \strc_sectioning_after_yes ...l \c_strc_sectioning_auto_break \spac_vspacing_same_page \currentheadlevel \plusone \fi \strc_sectioning_empty_correction \headparameter \c!after \strc_sectioning_depth_correction \fi <macro> \strc_sectioning_handle ...synchonization \let \getheadtitle \fullheadtitle \strc_rendering_place_head_text \dostoptagged \strc_sectioning_after_yes \orelse \ifconditional \c_strc_sectioning_hidden \strc_sectioning_register {#1}{#2}{#3}\strc_sectioning_report \let \gethe... <macro> \syst_modes_set_yes #1->\settrue \c_syst_modes_set_done #1 \doifelsenextoptionalcs \syst_modes_set_start \syst_modes_set_quit <macro> \CoverPageTitle \startmodeset [**en, **uk] {\hiddentitle {[Cover page]}}[**es] {\hiddentitle {[Portada]}} [**deo,**de,**de-de,**de-at,**de-ch] {\hiddentitle {[Bildtitelseite]}}\stopmodeset <macro> \22>:coverpage ...,**de,**de-de,**de-at,**de-ch] {\hiddentitle {[Bildtitelseite]}}\stopmodeset }\doifdefined {hiddentitle}{\CoverPageTitle } \setupbodyfont [svb]{\scale [width=.35\textwidth ]{\sc \getvariable {coverpage}{author}}}\vfill \scale [width=\textwidth]... \setuppapersize[A6] Would it be possible that LMTX adds the undefined command at the end of the tex error line? I mean something similar to: tex error > tex error on line 9 in file cont-yes.mkiv: Undefined control sequence (vskivskip) It would help a lot to detect wrong commands. Many thanks for your help, Pablo -- http://www.ousia.tk