If you are trying to download items (including dependencies) that add up to more than 100mb, you'll get that message. Try reducing the amount of items you download at one time. Or, if you know what the dependencies are, try downloading some of them first, before downloading the original items you were trying to download. I had to do that recently with a route that had a lot of dependencies I didn't already have, which sent my total download to well over 100mb.