Why does ConTeXt fail to compile when using custom fonts and a bulleted list?

\starttypescript[serif]                    [titillium]
    \definefontsynonym[Serif]            [file:Titillium-Regular]
    \definefontsynonym[SerifBold]            [file:Titillium-Bold]
    \definefontsynonym[SerifItalic]            [file:Titillium-Italic]
    \definefontsynonym[SerifBoldItalic]        [file:Titillium-Bold-Italic]
\stoptypescript

\starttypescript[sans]                    [titillium]
    \definefontsynonym[Sans]            [file:Roboto-Regular]
    \definefontsynonym[SansBold]            [file:Roboto-Bold]
    \definefontsynonym[SansItalic]            [file:Roboto-Italic]
    \definefontsynonym[SansBoldItalic]        [file:Roboto-Bold-Italic]
\stoptypescript

\starttypescript[calligraphy]                [titillium]
    \definefontsynonym[Calligraphy]            [file:Arizonia-Regular]
\stoptypescript

\starttypescript[handwriting]                [titillium]
    \definefontsynonym[Handwriting]            [file:Pacifico-Regular]
\stoptypescript

\starttypescript[titillium]
    \definetypeface[titillium]                [rm][serif][titillium][default]
    \definetypeface[titillium]                [ss][sans][titillium][default]
    \definetypeface[titillium]                [cg][calligraphy][titillium][default]
    \definetypeface[titillium]                [hw][handwriting][titillium][default]
\stoptypescript


\usetypescript[titillium]
\setupbodyfont[titillium, 12pt]

\starttext

    \startitemize
        \item This is an item.
        \item This is another item.
    \stopitemize
\stoptext

When I compile this, it reports:

tex error > error on line 38 in file /tmp/test.tex: ! Math error: parameter \Umathquad\displaystyle is not set

• If I change the bulleted list to an enumerated list, e.g. \startitemize[2] changed to \startitemize[n], then it compiles fine.


• If I change the bulleted list to default list, e.g. \startitemize[2] changed to \startitemize, then it similarly fails to compile, reporting the same error.


• If I instead keep the bulleted list, but delete the custom typescript, it compiles fine.


• I tried switching all of the fonts to entirely different fonts, but it similarly failed to compile.

How can I compile the document with custom fonts and a bulleted list?