Why is my computer having problems playing multi-player games on wifi?

I enabled every single option for him on the link you sent me above. Still gets the same error message.

To answer your questions:

I am doing this online using my computer, not the Xbox. He has no problems with minecraft on the Xbox - it can connect to play multi-player just fine. He has no problems with multi-player with other games on the XBox. He doesn't play any other Xbox games
on his chromebook so we have no way of knowing if there are other problems there.

Why would you have to pay another $10 to play the multi-player? The game contains the single-player and the multi-player as is. You don't have to pay extra for it.

Are you asking about the DLC "From Ashes"?

I don't get this. Why do you "have" to play the multi-player? There are people here who haven't even touched multi-player and some who only got into it after beating the game. All the Multi-player does is give you extra Military Strength to give a very slight
alteration to the way the game could end for you. Again, it's not like you have to play one to a certain point before you can play the other.

for multi-player games-yes why not

for single-player games-hells no

My favorite game was Halo CE, I really love this game and I used to play the multi-player the whole day with my friends, I always wanted to be the best player on the whole server. I currently have the master chief collection and I'm still playing the multi-player
like the first time.