There is a bug where if you switch users on your computer, the server does not kick you, but still thinks you are online. So as a result, tab lists don't show your name.
Also, logging into a server from another computer while logged in from another computer triggers this event.
Also, any achievements gotten in that time period are nullified, but others see you get it while you are in ghost mode.
How to recreate:
1. Log into any server.
2. switch users on your computer without closing minecraft.
3. go back and hit tab.
Another way:
1. Log in as usual.
2. Without logging out, go to another computer.
3. Log into the same server; you'll see a leaving message, but not joining message.
4. Hit tab.
I can still comment and play minecraft as usual though.
In the first picture, you can see I am in the chat as ClassicPork
In the second picture, I am holding tab, but my name does not show up.
Keywords i searched for prior to this:
TabList
Tab list
Player listing
switch user computer
switch user
player list switch user
14w20b
Related issues
Attachments
Comments


Switch user without closing Minecraft ? How's that possible ?

Please force a crash by pressing F3 + C for 10 seconds while in-game and attach the crash report ([minecraft/crash-reports/crash-<DATE>-client.txt|http://hopper.minecraft.net/help/finding-minecraft-data-folder]
) here.
It is possible to switch users, hit escape, then switch users without closing it. It is simple.

It is possible to switch users, hit escape, then switch users without closing it. It is simple.
Aha.
Didn't get that part then switch users . How exactly ?
Got it.
Still a concern in 14w21b

Is this still a concern in the current Minecraft version? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases. If this has been done, we can reopen the issue.
Keep in mind that the "Resolved"-Status on this ticket just means "Answered", and that we are waiting for further information on whether this issue still exists or not. We will reopen it as soon as the requested information has been delivered.
Ticket resolved as incomplete, because no answer in a reasonable amount of time (1+ year), if it still happens, please update the ticket.