🚀 go-pugleaf

The REASON you get this cryptic message when you leave off the ending
macro for a footnote (or whatever) is that nroff is trying to save the
entire remainder of your file as the text of the footnote, and can't
handle it.  (If the remainder is short enough that it CAN be handled,
said remainder and the original footnote text will simply disappear.)

The proper fix for this is not really a fix to the error message, but
a fix to the macro package to check for unterminated footnotes in
various places.  The message can occur for other reasons;  it basically
means "something went wrong", and can't get more specific without a
high probability of being wrong at times.

People who run into this, please let me have a look at the file in
question;  I need a better idea of where the macros should check for
this problem.

P.S. It's .SF, not .EN, to end a footnote.