Server not responding error when loading content [SOLVED]

I currently get a “Server not responding” message when trying to load content that I actually have purchased. Also, projects with that content give me a watermark. My internet connection is fine, so I would like to know how to get around this as I have to complete something with some urgency.

Obviously, Activate Purchased Items is not a solution as the server is not responding.

It must have been a temporary glitch, because my other PC was OK. So I just rebooted and no more watermark!