I am a huge fan of DDG and use the search engine as my default. Unfortunately, this plugin appears to be incompatible with duckduckgo.com--it causes a redirect loop and the page fails to load. You should already have most of the features it provides through other recommended Firefox extensions, so I think disabling it is the way to go for now. I also think I was missing a lot of the annoying features because ublock blocked them--lol!