Was having same issue. Are you using Chrome? I opened my account again Firefox and the Save to Desktop download worked.
Can you take some screenshots of how you are downloading them? If it is a matter of the image saying you need to license it, it is almost always a browser issue. Chrome with any browser add ons will cause this very frequently. Also try clearing your browser cache.
If you are still getting the watermarks then try the method in the screenshots in the post here: I purchased a a stock image and I cannot seem to download the licensed image without the watermark?? Please assist