What gameplay feature is this bug affecting?
Den page, my profile

What's the issue? Please include any error messages you receive and as much detail as possible.
I can't add a profile picture (Avatar) to my account. I've just created this account, which is my side account, and I wanted them to have the same profile picture. So, I copied the imgur link from my main account and pasted on this account's settings. However, the following error message appears: "Your details have been saved. However, your avatar was not saved as we couldn't find it. On your next clickthrough, the layout will change.", and it doesn't let me apply the image as my profile picture.
I've already tried copying the image's link from imgur itself, tried two or three different link formats from imgur, and none of them worked.

Any links relating to this bug? For example, if a particular lion is bugging, what is the link to that lion?
My own page.

Any screenshots you can provide us with?
https://i.imgur.com/wLpbToN.jpeg

Please provide us with step by step explanation how this bug happened so we can attempt to replicate it. If it's complex, please include screenshots where possible:
Go to your den page > Paste a link in the Avatar URL > Click "Save"