Hello Andy,
I am having a similar issue except my error comes from a blogger.com website (www.brand-lounge.nrdigitalbranding.com). I have setup the Twitter Card information a while ago and it worked fine, however it just disappeared recently - I get the same error as Crystal:
INFO: Page fetched successfully
INFO: 5 metatags were found
ERROR: No card found (Card error)
This is the code I have in my Blogger template (right before the tag):
<b:if cond='data:blog.pageType == "item"'>
<b:if cond='data:blog.postImageThumbnailUrl'>
<b:if cond='data:blog.metaDescription'>
<meta content='summary' name='twitter:card'/>
<meta content='@nemki' name='twitter:site'/>
<meta content='@nemki' name='twitter:creator'/>
<meta expr:content='data:blog.pageName' name='twitter:title'/>
<meta expr:content='data:blog.metaDescription' name='twitter:description'/>
<meta expr:content='data:blog.postImageThumbnailUrl' name='twitter:image:src'/>
<meta expr:content='data:blog.homepageUrl' name='twitter:domain'/>
</b:if>
</b:if>
</b:if>
</head>
Could you please let me know why this happens all of a sudden when it used to work before, and how it can be fixed?
Thanks,
Nem