cant play games

Yes, this happens with a lot of Demos, yes i cleared cache, and it didnt help, no, i have connected only Portable device (flash memory) Also, today i have downloaded Mass Effect 3 Demo, and it also says press start, but nothing happens.

Please delete the system cache by typing the "Y"-button while choosing your HDD in the settings menu.

What specific game demos do you mean?

Hi there,

please try the manual power cycle steps like mentioned on the following link, be sure to wait at least 60 seconds before powering on again:
http://support.xbox.com/en-us/xbox-one/console/power-cycle-console

If that doesn't help and if the games are located on an external hdd then try disconnecting and reconnecting it.

If the games are installed on the internal storage, try removing the game and reinstalling it.

Let us know the results

Hello! I'm not entirely sure what your issue is. Can you tell us what you are trying to do and what is happening when you try. Thanks!

Hey mate, can you tell us if you're receiving any error messages, as Grey inquired above? Also, how did your friend test your profile? Did he use your account on his console? Please provide as much detail as possible.