Game says I need to be online to start game but it's offline

Try power cycling by holding the power button on the console for 10 seconds until it shuts down to see if that helps.

Thanks for your help!

I tried solution 1 - still doesn't work.

re solution 2: 3 games are already installed (online installation). I tried two of the games - they work fine if I'm online. If I start the console online then go offline the games still work. If I go offline, turn xbox off (actually unplug it since I will need to move it), turn xbox on the games ask "Who are you" and says "make sure you're connected ..."

When I start Xbox offline, I select 'Skip sign in'. (I'm a newbie so winging it ... skip sign in made sense since I was offline. I later tried clicking (like i do when I'm online) but that didn't work - wanted me to connect.)

The very first time I moved the xbox to the outside room and played offline it worked! The next day I turned it on and when I tried to start the game it said "who are you" ... lol short memory!

Thanks again for your help.

Normally it will be because the game requires an update to be played online there should be an option for this when you start the game and if you say no you will have to remain offline.

A hard reset may solve this problem.

Hold down the power button until the system shuts down and unplug the power cable.

Wait for 5 min and plug it back in and restart the console

Try going to your network settings and turning your console offline.