This issue has been plaguing me for a few months. It doesn’t seem to have a pattern - games just disconnect after 5 - 20 minutes when playing on the Roblox Client. Games outside of Roblox do not have this issue for me.
Windows 10
Gigabit internet
Decent PC
Wifi connection
Been experiencing this issue here.
I’ve done extensive testing of all my switches, router/firewall, and everything on my end is perfect. However, I experience near consistent 277 errors almost everyday. I’ve even tested different ISP and a hotspot to see if it would resolve, with no success.
My building game has been having this issue since middle of November more or less.
It’s very odd but whenever a player tries to rotate a part with a drag tool the game crashes and error 277 is shown. I did not write the code for the drag tool but when this action is called a remote event is triggered by the client to fire this event on the server so it seems like a networking issue.
Bumping this thread because it’s still an issue. Unlike what OP has said, it seems that all games are affected, some more, some less, but all of them are. This is really annoying, and sometimes even gamebreaking if games teleport players around places a lot.
This is still happening, recently my game has had multiple occasions of the server crashing with this error.
This happens to my friend, Hydriin’s, game Quantum City which we made for a school project whenever he tries to play it. Weird part is, he can Run the game no problem.
Edit: He can Run the game in Studio no problem.
Bumping once more as I’m experiencing this problem myself on all games and even Studio when in a teamcreate. I have encountered this same issue on other devices (both mobile and desktop) as well.
I’m having the same issue, this started roughly about 4-5 days ago and I can’t play most games without getting this error once for the first time I try to join, or I can’t even play them at all.
Update: It happens on these games and started about a week ago.
🌳 Lumber Tycoon 2 - Roblox (50%)
Jailbreak - Roblox (100%)
Deathrun 🏃♀️🎉 - Roblox (100%)
Hotel - Roblox (25%)
I’ve tried restarting my PC, disabling and enabling all networks in Control Panel, cleared all Internet Options. While playing a YouTube video in the background, it does not shut my internet down, however the only website that starts to have problems is Roblox. A couple seconds after, the Roblox website starts working for me. I really don’t know what is causing the problem.
I’ve heard that (Error Code: 277) means that you’ve been kicked by the server. However, I don’t know why it is happening.
Yeah, I’ve talked to a couple of friends, some of them have the same exact problem as me. We don’t know why it’s happening. I told them to try what I tried to do to fix the problem, same thing.
I just started getting this today, but only on one of my games. ???
Hmm… all of a sudden, fixed! 
And… back to 277… yarg. Not sure how this happens, but hopefully just gets detected and resolved on the Roblox side.
Can you leave a link to your game?
Not sure if you did something zeuxcg, but I’m guessing you did because I’m not having any further issues. Thanks for checking!
I am getting this error too at random times. In 1 of my games.
This also has been happening to be quite frequently. With my case, there is a slight change, instead of loosing connection, its shows an error with “Account launched from different device” but this could not have happened. I have 2FA to my phone email so no one would have been able to get the code. It’s really strange how this is happening.
Getting this a lot recently, at any game. I am in game for about 1-2 minutes before the “packets in resend queue” starts to go up quickly, then I promptly lose connection.