I am using MikTeX 2.9, and trying to get the reledmac package working with luatexja. Both packages work fine if I try to use them on their own, but if I combine them I get the same error whether or not there's actually any Japanese text in the file.
If I have both packages included in a file that doesn't try to use the reledmac features, it works (e.g. just a begin document, "hi", and end document). Japanese text works fine as well.
Here is a minimal sample that attempts to use reledmac:
\documentclass{article}
\usepackage{luatexja}
\usepackage{reledmac}
\begin{document}
\beginnumbering
\pstart
hello world
\pend
\endnumbering
\end{document}
If I comment out the \usepackage{luatexja} it works fine. But with that in there, I get the following error:
Section 1 (./untitled-2.1) (./untitled-2.eledsec1)error: ...a/Roaming/MiKTeX/2.9/tex/luatex/luatexja/ltj-jfmglue.lua:538: attempt to call field '?' (a nil value) .
to be read again \ltj@@reset@badness
l.9 \endnumbering
?
I would guess this to be some sort of encoding issue, but there's no actual Japanese text in the file.