CONSOLE MESSAGE: line 8: Namespace prefix foo on bar is not defined

layer at (0,0) size 800x600
  RenderView at (0,0) size 800x600
layer at (0,0) size 800x300
  RenderBlock {html} at (0,0) size 800x300
    RenderBlock {parsererror} at (16,16) size 768x196 [bgcolor=#FFDDDD] [border: (2px solid #CC7777)]
      RenderBlock {h3} at (18,20) size 732x24
        RenderText {#text} at (0,0) size 324x22
          text run at (0,0) width 324: "This page contains the following errors:"
      RenderBlock {div} at (18,62) size 732x16
        RenderText {#text} at (0,0) size 511x15
          text run at (0,0) width 511: "error on line 1 at column 110: Namespace prefix foo on bar is not defined"
      RenderBlock {h3} at (18,96) size 732x24
        RenderText {#text} at (0,0) size 430x22
          text run at (0,0) width 430: "Below is a rendering of the page up to the first error."
      RenderBlock {p} at (18,137) size 732x41
        RenderText {#text} at (0,0) size 692x39
          text run at (0,0) width 692: "This document was created as the result of an XSL transformation. The line and column numbers given are from the"
          text run at (0,20) width 112: "transformed result."
    RenderBody {body} at (8,227) size 784x57
      RenderBlock {p} at (0,0) size 784x20
        RenderText {#text} at (0,0) size 218x19
          text run at (0,0) width 218: "You should see error text above this"
      RenderBlock (anonymous) at (0,36) size 784x0
        RenderInline {foo:bar} at (0,0) size 0x0
      RenderBlock {p} at (0,36) size 784x20
        RenderText {#text} at (0,0) size 331x19
          text run at (0,0) width 331: "ERROR? this, and nothing below it should be rendered"