On Sat, 1 May 2021, Brian Revell wrote:
 I just clicked on the view Larger or Smaller icons on the bottom 
 rhs options to the right of the Edit Copy Save etc menus and the 
 error message sprang up. 
Ah, I see an error on resizing the plot when the confidence interval 
is shown as a shaded area rather than error bars. That's now fixed 
in git; the fix will be in the next release.
Tech note: when we resize a plot we add a "linewidth" directive so 
that gnuplot will make the lines thicker or thinner. But that's not 
valid if the element to be plotted is not a line, as with a shaded 
area (or "filledcurve" in gnuplot lingo).
Allin