This morning, 12/14/15 from about 8:00 AM PST to 8:40 AM PST, some users may not have been able to view assignment submissions from Speedgrader due to an issue with Crocodoc, which is the tool in Canvas that enables users to preview and annotate files.
Students were still able to submit their assignments, and instructors were still able to download the files in order to view them offline, as well as use Speedgrader to enter grades and feedback.
The issue was resolved and service was restored around 8:40 AM PST. For more information, please see the Canvas Status page.
If you need assistance or would like to report an issue, please submit a Help Request.