Trello and Firefox beta

Off Topic
1

When I try to view the TU Trello, all I can see is a white page with a solid blue bar on top.
Anyone else unable to view the page on Firefox stable or beta? I’ve checked all my add-ons and so far been unable to resolve this.
It wouldn’t surprise me if the beta is the issue, it has caused problems with other sites for me in the past.

2

I also saw that bar. But after a few seconds the page loaded normally:

Bildschirmfoto vom 2016-08-29 20-54-42.png1920×1080 678 KB

3

Running 49.0b7 myself.