I had another look, be as it may, this cloudfare loader leads the javascripts required by the template manager not to load. It loads the scripts, but they are all empty. That causes the hickup, first it was a hunch that it had to do something with that, but now I am pretty sure.
That loader file tries to improve javascript load times, you can read up on it here:
support.cloudflare.com/hc/en-us/articles...es-Rocket-Loader-do-
If you take a closer look, all javascripts are now empty.
Hi Roeland_A!: