Hi @benjamin,
Thanks for your interest, yes it looks like one of the CodeMirror lib loaded by L&L is involved in this conflict.
I temporarily fixed the problem by dequeuing the libs, which allows to edit MMM HTML widget again:
add_action( 'wp_print_scripts', function() {
wp_dequeue_script('tangible-codemirror');
wp_dequeue_script('tangible-codemirror-csslint');
wp_dequeue_script('tangible-codemirror-htmlhint');
wp_dequeue_script('tangible-codemirror-jshint');
wp_dequeue_script('tangible-codemirror-jsonlint');
wp_dequeue_script('tangible-codemirror-scsslint');
}, 20 );
i’ll try to limit the dequeuing to the Lint lib you’re pointing at and see if it works.
[Update]
All the libs above need to be dequeued except tangible-codemirror-jshint that can be kept.
Otherwise, the b.verify is not a function error triggers.