Hello,

I'm facing a problem, not sure where the problem really is (I'm not a Python developer), but I managed to create a little use case showing it.

Using fresh install mkdocs (1.1.2) and markdown 3.3.3 (problem is not here with markdown 3.2.2)

This .md file works

A text Another text `<?php`. <div> hello </div>

Adding a new line, and it no longer works with error AttributeError: 'NoneType' object has no attribute 'end'

A text New line Another text `<?php`. <div> hello </div>

It also fails with other combinations of code tags containing HTML and/or PHP. But this one is the smaller use case I've found.

Thanks!