Hello, I have two identical files, one named main.ctx.tex and the other tmp.ctx.tmp. The latter was made by copying the former. Both files contain just this: \starttext \stoptext %%% Local Variables: %%% mode: context %%% TeX-master: t %%% End: tmp.ctx.tex compiles fine, but main.ctx.tex fails with this error: system : main.ctx.top loaded (./main.ctx.top) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo) (./main.ctx.tuo ! Missing \endcsname inserted. <to be read again> \let \noshowargumenterror ->\let \expectedarguments \noexpectedarguments \dotripleempty #1->\noshowargumenterror \doifnextcharelse [{\dotripletestemp... <argument> ...oss \fileprefix fig:\externalfigure [dummy \ifundefined #1->\unless \ifcsname #1 \endcsname \mainreference ...ined {\r!cross \fileprefix #1#2} \ifcase \autocrossfilerefe... l.11 ...re [dummy}{2::0:0:0:0:0:0:0::2}{2}{{1}{]}} ? x No pages of output. Are some filenames forbidden in Context? Puzzled, Roger