When you choose an image in the Buddypress Activity Stream to upload, instead of showing it as a preview, it disappears. If I click on the status box again, it will reappear. I rolled back to version 4.4.8 and it then works fine, however it is present in version 4.5.1 and 4.5.0. I am using Socialize Theme and the url of my website is below:
(Please note that it is currently rolled back to 4.4.8 so it is working right now)