Hi Myles,
I'm sorry you are running into this issue. The published file in Google Web Designer 2.0.0.1113 build contains the dynamic meta tags for the new AdWords UI. However, we are about to release an update to not include those tags yet to continue to support the workflow in the current AdWords UI. The release should be out in an hour. The new version will be 2.0.0.1116. You will need to re-publish the file to fix the issue.
In the mean time, if you want to proceed, please open the index.html in a text editor and remove the following tags in order to publish the the current AdWords UI:
<meta name="productType" content="dynamic"><meta name="vertical" content="RETAIL">
If you would like to check out the new AdWords UI, you will need these meta tags for dynamic remarketing creatives.
Thanks,
San
Google Web Designer team