External Hard drive stopping xbox one from starting.

If it worked BEFORE the Preview I suppose it's possible that it's the Preview. Have you checked the Preview Forum to see if anyone else has had the same issue? If not, I'd try that?

I have the same issue on both my xbox one systems. One system has preview and the other does not. I assume it is the external drive , Western Digital 1TB.

The external hard drive was around 20% full. After the I formatted the external hard drive it went down to 0% as everything was uninstalled. Thing is i tried transfering Battlefield 1 from the internal hard drive to the now empty external hard drive and
it started transferring. Battlefield 1 was one of the games that just stopped installing/transferring when i wanted to move from the internal to the external hard drive so i might of fixed the problem. Now i am just concerned that the games that were uninstalled
will not have anyting saved and i will have lost everything.

if you are trying to install them in an external hard drive for the xbox 360 then that might be the problem, if it is possible, try to install them in the internal hard drive of the console, once you do that try to start the apps and to check the external
hard drive is not damaged try to start a game from there

You can get external hard drive. You can them at game stop if you want one xbox specific, but you can get a toshiba 3t external hard drive for pretty cheap, and about the size of a deck of cards.