Mismatched package date
Sorry, I uploaded the fixed version (20211024.0) to CTAN.
when a previous version is detected
\LuaTeXjaversion can be used for this. (Since LuaTeX-ja 20211024.0, the identification message
Package: luatexja 2021-10-24 Japanese Typesetting with Lua(La)TeXis generated from the value of \LuaTeXjaversion.)
Hello! Since the 2021/09/18 version of the luatexja package provides an very important feature for me, I attempted to check the date of the current luatexja package and throw an error message when a previous version is detected in my LaTeX template, but found that the built-in date of the main package is not up to date even though the package itself is updated. The related content of the output log file is presented as follows.
(.../tex/luatex/luatexja/luatexja.sty Package: luatexja 2021-06-07 Japanese Typesetting with Lua(La)TeX
(.../tex/luatex/luatexja/luatexja-cor e.sty Package: luatexja-core 2021-05-21 Core of LuaTeX-ja