As discovered in this discussion, the wrong type of quotation mark character has been used at the end of the URL in the HTML template in this article:
<img src="http://img.geocaching.com/stats/tb.aspx?guid=##############”>
Notice that a "right double quotation mark" (U+201D / ”) has been used as the second-to-last character, rather than the standard "quotation mark" (U+0022 / "). When copied and pasted into a trackable or cache listing description, this character a