I am cross-posting a message I sent to computer.text.tex, since the problem affects LyX.. Lars Madsen's (memoir's maintainer) temporary fix is reported at the end.
I think I have stumbled upon an incompatibility between memoir and Lyx. Memoir uses the \pagenote command to produce endnotes. However, pagenote fails when the text of the pagenote has a comment sign (i.e. '%') before the closing brace. Which is exactly how Lyx produces footnotes: Minimal example: \documentclass[a4paper,10pt]{memoir} \usepackage[english]{babel} \makepagenote \begin{document} 1. This works\pagenote{This is a pagenote} 2 This fails\pagenote{This is a pagenote% } \printpagenotes \end{document} The second format is how Lyx exports to latex. Any idea on how to solve the problem is welcome. Cheers, Stefano --------------Lars Madsen's reply----------------------- very interesting it is caused by \...@sanitize which is used when we write the pagenote to file, so we end up with \noteentry{2}{}{This is a pagenote% }{1} which of course crashes everything when LaTeX attempts to run the .ent file. Short term fix \makeatletter \renewcommand*{\makepagenote}{% \newwri...@notefile \immediate\openo...@notefile=\jobname.ent \mempagenotestrue \def\pagenot...@bsphack\begingroup % \...@sanitize \...@m@wrpnote}% \typeout{Writing note file \jobname.ent}% \let\makepageno...@empty} \makeatother \makepagenote