BuddyPress.org

Having problems uploading an avatar? Do they turn black? Do they not show up at all? Does the cropping tool malfunction?

https://buddypress.org/forums/topic.php?id=302#post-1212

https://buddypress.org/forums/topic.php?id=1960#post-10404

Some good advice on how to change blogs.dir directory permissions: https://buddypress.org/forums/topic.php?id=1153

Here is a rule of thumb. You do not want to try uploading too big or too small of an avatar file. By default, BuddyPress sets the small avatar at 50 by 50 and the large avatar at 150 by 150. So, if your source image is smaller than 150 on at least one of its dimensions, you could have issues with creating the large avatar. If it is smaller than 50 on at least one of its dimensions, you could have issues with creating the small and large avatar.

Finally, if you are still having issues after following the linked advice, you may have a WPMU plugin conflict–especially if you are using any plugins for image manipulation or display. Here is a list of plugins that can cause conflicts that users have reported to date:

1. NextGen Gallery
2. WP-cycle
3. lightbox
4. Dynamic Content Gallery

To figure out if you have plugin issues, follow the standard WPMU protocol for determining plugin conflicts.