Hello Hans. With the current beta referencing lines is broken again. It used to work yesterday. Here is a test file and the error message: \starttext \startlinenumbering \input tufte \someline[lin:b] \startline[lin:a] \input tufte \stopline[lin:a] \stoplinenumbering \inline[lin:b] \stoptext ! LuaTeX error no string to print stack traceback: [C]: in function 'texsprint' ...text/tex/texmf-context/tex/context/base/strc-ref.lua:840: in function 'get_current_prefixspec' <main ctx instance>:1: in main chunk. \currentreferencecontent ...ixspec("\v!default ")} )} <argument> ...freference \currentreferencecontent \the \rightreferencetoks \... \doifelsenothing #1->\edef \!!stringa {#1 }\ifx \!!stringa \empty \expandafte... <argument> ...ghtreferencetoks \rightofreference } \dosymbolreference \dowant... \firstoftwoarguments #1#2->#1 \dodoinatreferenceindeed ...eference {#1}{#2}[#4]} \endgroup ... l.9 \inline[lin:b] Thanks in advance! Andreas