# Problem with un-clear error messages (using LaTeXmk[fls file] and XeLaTeX[bad file descriptor]) [closed]

More or less out of the blue, I've gotten the following:

xelatex: Bad file descriptor
Latexmk: fls file doesn't appear to have been made


I've no clue about the first and the second is confusing in that the appropriate .fls file was created during the latexmk run. Since my text is mostly \input based, I narrowed it down to two files. One has undergone significant change so it is the likely target for investigation based on the debugging rule of whatever changed is the problem but the other was a simple inclusion for the bibliography which has not changed in quite some time. I've done a latexmk -C filename several times without improvement. It creates the .pdf file but still fails with:

Latexmk: Errors, so I did not complete making targets
Collected error summary (may duplicate other messages):
pdflatex: Command for 'pdflatex' gave return code 256


As an aside, where does Latexmk put the errors is finds and 'collects'? Nor can I seem to find what 'code 256' actually means.

Suggestions, brickbats, pointers all welcome at this point.

UPDATE: Here is a MWE that duplicates (at least for me) the problem:

First the test.tex file:

\documentclass{memoir}
\begin{document}
\input{bibliography}
\end{document}


Then the bibliography.tex file as \input above

\nocite{*}
\bibliographystyle{plain}
\bibliography{test}


And then the actual test.bib file:

@book{Bateman.1906,
author = {Bateman, Newton and Selby, Paul and Short, William F.},
year = {1906},
title = {Historical encyclopedia of Illinois},
publisher = {Munsell Pub. Co.}
}

@book{Beckett.1966,
author = {Beckett, J. C.},
year = {1966},
title = {The making of modern Ireland, 1603-1623},

UPDATE II: Just in case here is the latexmkrc file I use:
$pdf_mode =$preview_mode = 1;
$dvi_mode =$postscript_mode = 0;
$pdflatex = "xelatex %O %S";$hash_calc_ignore_pattern{'dat'} = '^.*$';$pdf_previewer = 'start "c:/Program Files/SumatraPDF/SumatraPDF.exe" %O %S';