When I try to use canvas on my iMac not everything on the page will load. I can see the menu but the actual content is just blank. So I can click on modules or grades but the pages are blank. I have a 2012 iMac and have tried in both Firefox and Safari with no luck. But everything works just fine on my 2016 Macbook Pro. I'm at a complete loss as to what is going on and how to fix it.