JavaScript MathJax_Blank font error

Just noticed this, I get this error in Firefox's error console with my configuration. Any idea what's going wrong?

downloadable font: download failed (font-family: "MathJax_Blank" style:normal weight:normal stretch:normal src index:0): status=2147500037
source: about:blank
@font-face {   font-family: "MathJax_Blank";   src: url("about:blank"); }

Thanks, -nageh

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Yes, MathJax uses this to test the behavior of the browser when a font doesn't exist. There does not seem to be a way to trap the error to prevent the console message.

Davide