Processing a table of contents with the latest standalone (ConTeXt  ver: 2019.01.28 16:58 MKIV beta  fmt: 2019.2.3) fails with the following message:

luatex warning  > hpack filter: error: ...eXt/tex/texmf-context/tex/context/base/mkiv/typo-dua.lua:422: attempt to compare number with nil


tex error       > tex error on line 18 in file c_Contents.tex: ?



\strc_itemgroups_make_symbol_box ...mbol \fi \fi }

                                                  \let \strc_itemgroups_extr...

\strc_itemgroups_insert_item ...s_make_symbol_box 

                                                  \strc_itemgroups_make_dest...

\strc_itemgroups_start_item ...groups_insert_item 

                                                  \dostoptagged \ifcondition...

<to be read again> 

\dotagsetitem 

\sym ..._symbol \startitemgroupitem \dotagsetitem 

                                                  \s!symbol 

l.18 \sym{0.}

            Prolegomena to the Study of Hellenistic Astronomy


This worked with the previous standalone.

Alan