I get that message even when I'm on Wifi. Why? And there's no 'Download Manager' app to clear cache for or adjust settings.
We certainly want to make sure you can download all the items to your phone, tesexton. Let's take a look to see why you are still getting this error. What specific make and model phone do you have? What are you attempting to download when you get this message? When did this start?
NicoleR_VZW