CAT error usually means your friend hasn't downloaded the latest update. Tell them to check for updates. If that doesn't help, try deleting the game and installing it again.
Also, it would be a lot easier to help them if your friend came here for support instead of speaking through you.
English
-
Hi Im Swat
Bungie fan. Been here for 16years! - 오래됨
Then the only solution I can think of is to install the game instead of streaming it. Your friend will have a much better and lag-free experience by playing it directly from the console SSD instead of streaming it.