Well based on your source code I can see what's potentially wrong, the meta element itself will require both a name and a content attribute as below:
<meta name="" content="">
If however the thing you're using makes use of XHTML rather than HTML, you need to ensure that the element is closed properly with the / before the closing bracket:
<meta name="" content="" />
If it's still giving you an error I recommend putting it through the W3C validator (http://validator.w3.org/).
Having meta with property="" will cause errors because property isn't a valid attribute in HTML.