In strc-flt.mkvi \c!suffixstopper is undefined \unexpanded\def\thecurrentfloatnumbersuffix {\doifsomething{\floatcaptionparameter\c!suffix} {\floatcaptionparameter\c!suffixseparator \floatcaptionparameter\c!suffix \floatcaptionparameter\c!suffixstopper}} Perhaps it need to be added to \setupcaptions ? \setupcaptions [\c!location=\v!bottom, \c!grid=, \c!before=, % not used (yet) \c!inbetween={\blank[\v!medium]}, \c!after=, % not used (yet) \c!spacebefore=, \c!spaceinbetween=, % replaces fuzzy inbetween dual usage \c!spaceafter=, \c!width=\v!fit, \c!minwidth=\v!fit, % id est: the width of the floatbox in some cases \c!headstyle=\v!bold, \c!headcolor=, \c!leftmargin=\zeropoint, \c!rightmargin=\zeropoint, \c!outermargin=\zeropoint, \c!innermargin=\zeropoint, \c!setups=, \c!style=\v!normal, \c!color=, \c!textstyle=, \c!textcolor=, \c!align=, \c!number=\v!yes, % \c!expansion=\v!no % \c!prefix=\v!no, % \c!prefixconnector=., % \c!way=\v!by\v!chapter, % \c!prefixsegments=2:2, % \c!way=\@@nrway, % \c!blockway=\@@nrblockway, % \c!sectionnumber=\@@nrsectionnumber, % \c!separator=\@@koseparator, % \c!starter=\@@kostarter, % \c!stopper=\@@kostopper, \c!suffixseparator=, % currently rather hard coded \c!suffixstopper=, %% added \c!suffix=\floatcaptionsuffix, \c!distance=1em, \c!conversion=\v!numbers, \c!command=] -- luigi