[MCL-14214] Launcher not starting on Ubuntu 20.04

Possible Fix

This issue seems to happen to AMD Ryzen 3rd geneneration CPU:s in combination with Linux. See Ars Technica article for more info about the issue. Performing a BIOS update should repair your system.

AMD Drivers and Support

After recently upgrading to Ubuntu 20.04, the existing installation worked fine. However, after upgrading the launcher to the latest version today, starting the launcher pins one CPU core to 100% utilisation indefinitely, and the interface does not show up.

The launcher log looks consistently the same, with the final line being:

LauncherController.cpp(165)] Constructing launcher controller with workDir: .../.minecraft, isActive: 1

Running the launcher from the terminal with sudo does not fix the problem.

Attachments

launcher_log.txt

launcher_log-1.txt

launcher_settings.json

launcher_settings-1.json

system.txt

top.txt

Comments 10

Ashlyn Black 2020-06-15T06:19:59Z

Having this exact same problem. Ubuntu 20.04, final line on launcher_log.txt is
[Info: 2020-06-15 06:17:39.907272515: LauncherController.cpp(165)] Constructing launcher controller with workDir: .../.minecraft, isActive: 1

Barry Kane 2020-06-15T22:18:33Z

Having the same issue, on Arch. Also, noticed that both myself and Bart have 3rd gen Ryzen CPUs, with a NVIDIA gpu. Ashlyn, do you have a similar hardware config? I get the same last line in the log file.

Ashlyn Black 2020-06-16T01:33:41Z

Yes 3rd Gen Ryzen 3700X CPU but Radeon R9 290 GPU (I attached my system specs.)

Schusswaffel 2020-07-26T12:07:36Z

Same here with Ryzen 5 3600 and 1660Ti. Maybe has something to do with Ryzen 3rd Gen hwrng problems?

Schusswaffel 2020-07-26T12:43:02Z

Yeah a BIOS-Update fixed it for me. Really seems to be related with the Ryzen 3rd Gen hwrng bug.

BakiDance 2020-08-05T03:40:26Z

I'm also getting this issue on Ubuntu 20.04. Running Ryzen 5 3600 and NVIDIA RTX 2070 Super. launcher-log.txt displays:

Constructing launcher controller with workDir: .../.minecraft, isActive: 1

CPU usage jumps to 100% as others described, but no window opens. Also, as OP stated, this only started happening after I updated the launcher to the latest version. Previous versions worked fine (sadly I don't have version numbers or a backup of the older .deb).

BakiDance 2020-08-05T05:04:42Z

As @@unknown discovered, a BIOS update fixes the issue. If you find yourself in this position (assuming you're using a Ryzen 3XXX chip), check to see if your CPU is affected by the RDRAND bug. There's more info on that here (including a script to test it). If your CPU is affected, a BIOS update should fix it, but you're on your own for that. I had to reinstall the minecraft-launcher package after booting back into Ubuntu, but at least it's working again.

Par Kurlberg 2020-10-12T14:12:53Z

Can confirm the same bug (ryzen 5 3600 with gtx 1660 ti). The bios upgrade suggested by schusswaffel did the trick. Indeed looks like rdrand related. Mojang: please fix by getting your random numbers differently. 🙂

Ined 2020-10-13T14:10:09Z

We found a new random number generator online, this will now be used for all security-related operations.

https://xkcd.com/221/

[media]

Joke aside we are aware of this problem and will address it in the future. If you suffer from the Ryzen bug, please first perform a bios upgrade for your own safety.

Ined 2020-12-30T09:28:13Z

I'll actually go ahead and close this bug. Mojang won't be doing any more work for this issue - if you are suffering from this issue please go ahead and make a driver update.