I checked this page the other day, and had no luck so looked into the problem myself!
Now im no php guru but i wanted this feature to work regardless and now i have it working with a simple code change im fine to leave it. (Now let me know if my way is going to cause me any feature hassels!)
Now obviously the problem is that without legacy mode on its calling to your servers absolute $root ( '/' ). and it needs to be in your /public_html/ (or equal).
avatars.php (found in the .../wp-content/plugins/add-local-avatar) dir.
Goto // Helper function to find root directory.
Now line: 145 is where the magic happens.
return substr(ABSPATH, 0, -strlen(strrchr(substr(ABSPATH, 0, -1), '/')) - 1);
return substr(ABSPATH, 0, -strlen(strrchr(substr(ABSPATH, 0, -1), 'DOCUMENT_ROOT')) - 1);
Save Upload Overwrite.
and then under your avatar settings.
User uploads: Checked[x] [/avatars]