Multimc5: Authentication failure in game (after successful login with MultiMC)

[NotLogan]

System Information

MultiMC version: 0.6.2-1137

Operating System: Ubuntu 18.04 bionic (Budgie desktop)

Summary of the issue:

Authentication/sign-in within MultiMC works, game launches and detects servers; however, it fails to contact Mojang's authentication server.

MultiMC status icons detect auth servers are online.
Single player works perfectly, and using the official launcher does not have this issue.

What should happen:

The authentication from the MultiMC launcher should remain when launching the game

Steps to reproduce the issue:

1. Launch any instance within MultiMC after logging in.

2. Open up multiplayer and attempt to join a server. (servers should appear to be normal)

3. Error message: "Failed to login: The authentication servers are currently down for maintenance." (however, they are not down)

Suspected cause:

User account information transfer issue between MultiMC and the game itself.

Logs/Screenshots:

Minecraft: https://paste.ee/p/G3x1u
MultiMC: https://hastebin.com/osuhayujow.java

Additional Info:

I have tried Java 8 and 10 with identical results. And as I mentioned above, the vanilla client works without problem using the same install.

Reinstall does not solve issue
Applies to Lutris install and clean install (if that matters at all)

[vaxvhbe]

Hi,
I have the same issue, same OS (Ubuntu 18.04) and I tested Java JRE 8/10.
All work on the vanilla launcher.

[alex9752]

I have the same exact problem and situation. Also using forge gives me an error 255.

[QuImUfu]

Can not reproduce.
Joining a server with a fresh installation of ubuntu budgie works flawless on my PC.

[peterix]

This is a problem with Java, its SSL certificate store, and how things are packaged on 18.04.

Workaround:

sudo sed -i 's/keystore.type=\s*pkcs12/keystore.type=jks/' /etc/java-*/security/java.security
sudo rm /etc/ssl/certs/java/cacerts
sudo update-ca-certificates -f

Upstream bug: https://bugs.launchpad.net/ubuntu/+source/ca-certificates-java/+bug/1739631

[Janrupf]

So, had the same problem... if removing the certs does not work, purge all java packages (ALL).
This is going to uninstall MultiMC but your instances are not lost.
Use apt get install openjdk-8-jdk to install java. This may break dpkg/apt, but running apt install -f fixes it.
Now install MultiMC again and have fun playing on servers.

[peterix]

Upstream bug has Fix Released, closing.