Plutonium

Xerxes the one in the title of my post. I get a pop up saying

“Error:
An error occurred while creating a non matchmaking session.”

I’ve been getting this error after playing 5 to 7 rounds of zombies. Anyone know any fix?

I recently wanted to play with a Friend and when he finally got plutonium, he isn’t able to play. It lets him get into the server but then a pop up with “downloading game settings” is seen. We waited for minutes while the game was still in progress. To no luck, I am asking for anyone that knows how to solve this issue.