Okay, I maybe made some progress. I traced the code back and back through the various documents and found I have some items inside:

\startnointerference\startnointerference
My intent is to have items that are "there" but invisible to viewers, taking up no space on screen, but treated as being present, so the index will still point to that particular page.
This solution seems to be what's causing the [entry not flushed] error in the index.
Is there another solution instead of startnointerferencethat will hide text or any content but still allow page references to link to that blank spot?

--Joel

    On Wednesday, March 13, 2024 at 07:53:21 AM MDT, Joel via ntg-context <ntg-context@ntg.nl> wrote:  
 
 I have some custom registers that I use to index some information. When compiled, it just prints [entry not flushed] instead of printing some of the page numbers.
I have tens of thousands of lines of code, so have no idea how to break the problem down to a minimal example. What does [entry not flushed] mean? What kind of feature in my document do I need to search for that might explain why this is appearing?

Here is the minimal code used in my index, as you see it isn't showing the error, so something else in the document is causing it:

 \setvalue{W3}{this is text for W3}


\defineregister[learnedshort][compress=yes]
\setupregister[learnedshort][style=sansbold, textstyle=slanted, n=3, pagenumber=yes, indicator=no]
%
\defineregister[learnedlong][compress=yes]
\setupregister[learnedlong][style=sansbold, textstyle=slanted, n=2, pagenumber=yes, indicator=no]
%
\define[1]\learnedis{%
    \txt{} \getvalue{#1}
    \learnedshort{#1}
    \learnedlong{#1}
}
\define[1]\learned{%
    \textreference[textref#1]{\expanded{\currentstructuretitle}}
    \reference[ref#1]{}%
%
    \learnedshort{#1}
    \learnedlong{\getvalue{#1}}
}

\starttext

\learned{W3}

        \startchapter[title=Standards]
              \placeregister[learnedlong]
        \stopchapter
\stoptext


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