Microsoft will be rolling out the latest Xbox One Preview build later tonight. This appears to be a minor update to fix an install issue with universal apps.
The official Xbox forums have the info on this patch:
OS version released: rs1_xbox_rel_1608.160816-1851
Available: 6:00PM PDT 8/17 (1:00 AM GMT 18/8)
Installation - Resolved an issue which could cause installation errors with certain universal apps.
Update In addition, there should be a big improvement to Cortana's behavior as well. Microsoft's Zach Johnson explained the fix in a tweet:
As of today, when Cortana on Xbox is unsure what you asked her to do, she will ask for a confirmation before showing search results. Enjoy.
If you are a member of the Xbox One Preview program, you can check to see if you can download the latest update by double-tapping the Xbox button, then go down to All Settings, select System, then Console System & Updates, and it will tell you if the update is available.