Hi,
Apparently log files produced by MiKTeX TeX programs don't contain lines for \openout. This breaks the texi2dvi script used for converting Texinfo input to DVI, which looks for them. It would be desirable for this to be fixed, for the purposes of consistency and stability.
Problem was discovered with texi2dvi here: https://lists.gnu.org/archive/html/bug-texinfo/2015-08/msg00126.html
Thanks,
Gavin
This will be fixed in one of the next MiKTeX releases.
\openout is now enabled