ClassLink custom app icons, wallpapers, avatars might not load due to issues with Amazon Web Services (S3). Amazon has posted this on their status page and is actively working on fixing the issue.
Latest from Amazon:
11:58 AM PDT We are investigating increased error rates for Amazon S3 requests in the US-EAST-1 Region.
12:21 PM PDT We can confirm that some customers are receiving throttling errors accessing S3. We are currently investigating the root cause.
For more, go to https://status.aws.amazon.com/
If you have any questions or concerns, please contact us at firstname.lastname@example.org