Image upload hangs

[Mike Ferrier]

dragging an image into the browser causes it to be published in the chat for all participants; the progress bar fills up, but when complete, only the participant who pasted it sees the transition from the placeholder to the image -- everyone else sees the placeholder remain with a full progress bar. refreshing the page doesn't change anything, except that for the user who uploaded the photo, it reverts to the placeholder instead of the image itself.