I have been using our Sharepoint site on Firefox ever since we set it up a few months ago. Same for my coworker except he uses Chrome.
Just a few days ago suddenly we can't see Tasks when we open any of the tasks lists (all we'd see is "Tasks"...no timeline or list). In Chrome they eventually come up if you refresh the page a few times...they don't come up at all in Firefox. The other Sharepoint components seem to be fine, and all works fine in Internet Explorer.
The thing is, I'm on Firefox 31.0 and that was updated a month ago...we have certainly been using these lists since then. But of course Microsoft just wants to tell me it's a browser issue and I should just use Internet Explorer (which I really don't want to).
Has anyone else encountered this issue as well? Any ideas as to what the real root cause is (and how it can work in Firefox)? Thank you!