> Ok solved, was in the wrong folder :D
What was the right folder? I'm having similar problems and I'm thinking it was something silly like this :)
Answered my own question. For Steam users, the right path is NOT:
<install path>\exporters\html5\plugins.
Instead, plugins can go into:
<steampath>\steamapps\common\Construct2\Construct2-Win32\exporters\html5\plugins
and/or
<steampath>\steamapps\common\Construct2\Construct2-Win64\exporters\html5\plugins
I hope this helps someone!