Speedgrader - Website URL submission with no preview

[LUCASCAMPBELL]

In assignments, I frequently ask for screenshots to be taken and saved to their google drive. Using the shareable link, the students submit as a website URL.

When using speedgrader to grade these assignements: 

Sometimes I get a preview of the site like below:

But most often I get a black screen, forcing me to open in a new tab. Which makes the speedgrader a lot less speedy. 

Any idea why they aren't displaying a preview or how to submit differently so I always see a preview in speedgrader?

[Stef_retired]

@LUCASCAMPBELL  The second screenshot appears to be the result of a Google Drive URL rather than a link to a website. Are all of the blank submissions also Google Drive URLs?

[LUCASCAMPBELL]

Yes, they are. 

Because Google Drive uses a website URL for sharing (https://drive.google.com.......), I assumed that submission type would work for submitting links to shared items in google drive. 

[chriscas]

My guess would be a permissions issue on the google drive file.  If a student changes the permission to "anyone with link" or "public", Canvas should be able to get a preview. and show it in SpeedGrader  If the student adds you (the teacher) specifically as a viewer, co-editor, etc, Canvas will not have access to the file, and will likely just show a blank screen.  

-Chris

[LUCASCAMPBELL]

That was my first thought too, but the share settings are set to "anyone with the link" I tested it with another email address, outside of my organization even.