Why is my user profiles avatar upload not working?

I’ve got a multi-site network with buddypress and bbpress installed. BP is network activated but bbP is locally activated on the main domain. I’ve got numerous plugins. I can upload an avatar via the BP profile but not via the WP profile. I get the error message: “Upload error: File upload failed.” Is this the way its supposed to be. I don’t seem to recall this situation previously. I’ve tried deactivating a couple of plugins but not all. Still the problem persisted.