I am trying to create essay problems. I started by using the problems posted at the wiki. For example, the following problem is found doing a search on the Wiki for essay problems.

http://webwork.maa.org/wiki/EssayAnswer1#.Uj235MXft0w

I tried copying this problem into a text editor and then uploaded to a course to access via "local problems" using the browser.

I have tried several problems and I keep getting the same error:

Problem1 ERROR caught by Translator while processing problem file:WWprobs/Essay2.pg **************** Unrecognized character \xEF; marked by <-- HERE after ExPr__; <-- HERE near column 17 at line 1 of (eval 1915)

Here is the file I made that produces the above error:

DOCUMENT();

loadMacros("PG.pl","PGbasicmacros.pl","PGanswermacros.pl","MathObjects.pl");

#Load the Essay Macros

loadMacros("PGessaymacros.pl");

$m = random(2,5);

$b = random(20,30);

Context("Numeric");

Context()->variables->add(D => 'Real');

$F = Formula("$m D + $b");

$y1 = $F->eval(D=>1);

$y2 = $F->eval(D=>2);

BEGIN_TEXT

The cost to download data using your phone is a linear function of the amount of data downloaded. Suppose it costs $y1 dollars to download 1 gigabyte of data and $y2 dollars to download 2 gigabytes of data.

$PAR

Find a formula for the cost C in terms of the amount downloaded D. $BR

C=\{ans_rule()\}

$PAR

What do the slope and y-intercept of this function represent? $BR

\{#Put an Essay Box where ever you want a essay type answer\}

\{essay_box()\}

END_TEXT

ANS($F->cmp());

#Essay Boxs use the essay_cmp evaluator.

ANS(essay_cmp());

ENDDOCUMENT();