amp-script), chances are you have encountered this error:
Uncaught Error: Attempting to parse invalid HTML content
Forgetting to add a forward slash to an HTML closing tag, will make AMP complain that you are “Attempting to parse invalid HTML content.” As a result, the following error is generated.
[amp-script] Uncaught Error: Attempting to parse invalid HTML content. at (amp-script%5Bscript=%22myscript%22%5D.js:1)
But when you do include a forward slash, AMP will complain that you have an “Invalid or unexpected token.”
[amp-script] Uncaught SyntaxError: Invalid or unexpected token
mVar = "<div class='myclass'>My text</div>";
Unescaped closing tag: </div>
Escaped closing tag: </div>
Of course, these errors appear in different situations, but what I have mentioned is a valid cause for generating these errors.