What version are you running?
3.0.14
What's the URL of the page containing the problem?
users/
What steps will reproduce the problem?

Set the default Avatar Service to File Upload
View the Users list
Any user w/o an avatar shows up as broken


What is the expected output? What do you see instead?
To see the user list with a default avatar rather than a broken image
What operating system are you using? What browser?
Windows 10 / Chrome
Please provide any additional information below.
If the default avatar service is Gravatar the default avatar appears correctly