Avatars Are not Correctly Shown in Activity Stream Gadget
Symptoms
Either after an upgrade or moving your JIRA instance to another server, the activity stream gadget pictures appear to be broken.
This is what you see:
The image link appears to be correct and everything else works fine. If you go to the avatars page the images are correctly displayed.
Cause
This error occurs because the Activity Stream gadget gathers image links from the Base URL set on the administration interface. This error happens because the URL you set does not match where the instance is currently running on.
Resolution
Set a correct Base URL. You'll find out how to do it through the Global Configuration page, at Base URL.