Just a note to help someone else with this on a Samsung S5 LTE
could not be downloaded due to an error. (403)
Everything was going great with my brand new S5, until I turned on the Download Turbo.
Note, prior to turning on the booster, I was installing apps successfully over a WiFi connection.
I turned on Download Booster hoping to install apps from previous phone quicker.
Natural enough thing to do when you have 30 apps to get through, wouldn't you think?
All of a sudden I couldn't download anything from Google the Play Store.
Oddly, The Galaxystore (a wierd extra Play Store that comes with Galaxy Phones) worked, but most of my apps were not there, and those that were did not know I had purchased them.
After perusing the web, and resetting things and changing Google accounts, etc., I finally tried turning of my WiFi connection, and switching to only 4G mobile data.
Of course the S5's Download Booster was off now.
As if by magic, everything in Google Play Store started working again!
Okay, so maybe something in the Download Booster tries to make multiple connections to the Google Play Store server, and it doesn't like that.
So I turned off Download Booster, and turned on the WiFi, and turned off the 4G mobile data connection. Back to plain WiFi, as per the data connectivity configuration that was working in the beginning...
Alas, Google Play Store would not work again (same error), even with only WiFi on now.
Back to 4G, switch off WiFi, everything works on Google Play Store again. Consternation!
In summary:
If you have an S5 and you turn on the Samsung 4G + WiFi Booster and connect to Google Play Store, kiss your connectivity to Google Play Store via WiFi goodbye forever.
You can still connect with just 4G Mobile Data (as long as WiFi is off).
It's almost as if the Google Play Store server remembers indefinitely that you once tried to connect with WiFi and 4G together, and forbids your WiFi connectivity henceforth.