PHP campaignCreate - Error 311, Invalid HTML Content

I am getting an error code 311, "Invalid HTML Content", when I try to create a campaign.  See code below (with removed key numbers and urls).

$cm = new CampaignMonitor('xxxxxxxxxxxxxxxxxxxxxxxxxxxx');
$result = $cm->campaignCreate(

311: Invalid HTML Content
Your content contains JavaScript or Flash which cannot be sent to email clients.

I've simplified my HTML page down to the following and still get the error.


Either there is something required of an HTML page (doctype? I've tried that), or the API isn't working.  I can't imagine the API is broken, this is a key feature.  Any ideas?

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