I can't play anymore ... why?

It happened some times last month... but finally, game was coming... but not the 31... and nor yesterday nor today...

:)

 

I can't play online anymore!

Double NAT happens, when (at least) two devices are doing "Network Address Translation".

Your Router has only one internet connection, but "hides" multiple devices in your home (like your PC, Laptop, the console, a tablet and your smartphones) behind that one internet address.

So when data comes in from the outside internet, you need to tell the router to which device the incoming data has to be sent to.

The trouble is, that a lot of internet providers are running out of IPv4 addresses, and start to hide multiple customers behind a Carrier Grade NAT (CG-NAT) or tunnel network traffic through IPv6 via DS-Lite.

If you are stuck behind such a Carrier Grade NAT, incoming multiplayer data into your ISP wouldn't know if it has to go to your house, or to the Millers next door, or to Mr. Smith further down the street, similarly to the router not knowing if the incoming
data should be sent to your Xbox console, your PC or your sister's smartphone.

While you can set up port forwarding rules on your own router, and telling it, that Xbox Live data on a specific port has to go to the Xbox, there is no way to configure the router at your Internet Provider.

So please contact your internet provider, and ask them (if necessary, get a supervisor or someone with more technical knowledge) if you are put behind a CG-NAT with DS-Lite.

If so, ask your provider to give you a public IPv4 address that is not NATed.

 

I can't play online anymore!

Double NAT means you are having ports conflict on the router.

You can try the instruction here: Double NAT Detected in Xbox One Network Settings

Or in last choice you can reset your router. This will do a factory reset to the router and will erase any ports opened.