On Monday,  2 Oct 2017 at 15:39, Peter Davis wrote:
>> Very strange.  Try M-x toggle-debug-on-error RET and then post a
>> backtrace?
>
> Attached.

I cannot figure this out.  Maybe Nicolas will be able to help here.

> By the way, I tried filling in a tint value in the first row, and a PSA
> value for the middle row, but got the same error.

So it's not gnuplot, I would guess.  Could it be that you have a mixed
org installation?  Grasping at straws here...

-- 
: Eric S Fraga via Emacs 27.0.50, Org release_9.1.1-87-g3c83f1