Long story short, something is wrong with your dynamic tags. Two rules need to be applied:
1. Use ‘ but not “
Right version:
$!data.get(‘your_variable’)
Wrong version:
$!data.get("your_variable")
2. The tag was broken by another tag
Open the HTML editor of the entire message and Ctrl+F $!data.get(‘.
All the tags need to look like this $!data.get(‘something’). BUT! You may see something like this:
$!data.get(‘something' <span><strong>)
And these <span><strong> are what causing the error.