Some examples would be...
I have the Bible app on my phone. It has offline versions within that you can download. They always fail.
I have Firefox for my browser. Any download I attempt through that fails.
I have the Toneprint app from TC Electronics. It has updates for the different pedals, they fail.
Also... using an app called Circleback, an app that manages contacts, I get random network error notifications from this specific app.
I've check my network, and everything tests out fine. So I know I'm not just dropping connection. I've tried a few options that people have suggested for the errors I've read that state people can't even download the apps or updates from Google Play, but that hasn't fixed it either.