OK, hypothetical situation here but bear withme.
Imagine you have no access to internet ora phone signal because you're on a flight.
Your battery is about to collapse on one deviceso you need to get something onto another device.
What options are available? Well themost obvious one is Bluetooth.
But when it comes to Android it brings withit some caveats.
One being that you can't transfer all file types.
It might be an appor a save file from a game or an obscure document, sometimes Bluetooth just won't take it.
If the screen displays a file not sent message,you're going to have to do a little tweaking, which isn't that difficult.
The first thing you will need to is downloada file manager from Googleplay.
I recommend the comprehensive ES file explorer.
When youuse this application you'll be able to browse all the files on your device and if you longpress on a file you can rename it, and this includes the file extension type.
So simplyrename the extension to something Bluetooth will accept like a jpg file.
Try sending the file via Bluetooth again andyou should have no problems transferring that badboy.
The one thing you have to rememberis that you will need a file manager application on your source device too so you can replacethe fake file extension name with its true meaning.