@aaron D. Campbell
Thank you for your reply, However the error logs were empty.
@dwinden
Yes, Your correct on all my browsers on multiple PC’s they all use ublock origin.
The adblocker was blocking the following URL:
https://s3.amazonaws.com/downloads.mailchimp.com/js/mc-validate.js
The list\filter was Fanboy+Easylist-Merged Ultimate List? (forums.lanik.us)
White-listing this resolved the issue and returned functionality of the plugin.
The real question remains why did this 3rd party script “mc-validate.js” brake the plugin and why is it needed, Also it presents a risk, If someone hijacked that script with a malicious one then anyone’s admin panels are fare game.
I would really like to know what its for?