Adding Images to Posts

I am unable to upload images to my posts, either through direct upload or via URL. I’ve 3 different sub-domains on my account. All use the same theme, but I am only having this issue on 1 of the sub-domains. Everything still works as usual on the other 2. BlueHost tech support has looked into the matter and said there doesn’t seem to be anything wrong on the server side. I first starting experiencing this issue about 2 nights ago.