its some sort of update which couldent download properly download because of a server connection error.
read the error lol it said launcher.updater.download.download blaa blaa blaa, it said unknown source meaning the source of the whatever ur trying to get to is unavailable, it also said
java.lang.RuntimeException: Server responded with 404
server responded with 404 meaning you got the error '404'
this should explain what that means
https://www.lifewire.com/404-not-found-error-explained-2622936
meaning there is a error with your connection to a port. this could either be the server is gliched in that case there is nothing you can do but wait, or your connection/game connection is gliched...etc
try restarting your whole internet, [ like ur wifi ].
make sure your optifine and your mc version is EXACTLY the same. i mean i really dont know i havent used java in a long time just tryna help
gl - drepy
