MATLAB freezes at splash screen on Ubuntu

I am trying to start MATLAB 2018a on an Ubuntu machine. However, the application freezes at startup when showing the splash screen. I have attached a log file which shows the Java stack trace, starting with:

java.lang.RuntimeException: cannot load system cursor: CopyDrop.32x32

What I've seen from similar questions posed on this board seem to indicate it's related to a bug in Java and the X window system. It is possible to run MATLAB without GUI though and on a separate Windows machine I tried it also went without a hitch. I have therefore tried various other configurations such as running under GNOME, KDE, XFCE and on a different distro (Fedora), and rolling back to 2017a and 2017b. I have also updated OpenJDK. All are giving the same results. I hope someone knows of a workaround or, even better, a full fix.

[Rolling Osure]

Are you running Linux inside a virtual (cloud) environment? I have the same problem. Running on VirtualBox is fine but on an actual cloud environment with the same OS I get this error.

[Stefan van der Linden]

No, we are running this on 'normal' hardware. Interesting that it may work within Virtualbox. I'll give it a try, although this is not a workable solution for us at the moment.

Answer 1

[Rolling Osure]

Here is my final solution which worked on Ubuntu 16.04:

1- Edit following file:

nano /etc/default/grub

2- Edit the variable GRUB_CMDLINE_LINUX_DEFAULT to only have the content "nomodeset"

3- Run on terminal: sudo grub-mkconfig -o /boot/grub/grub.cfg

4- Reboot.

Matlab should now be able to start without any problems.

My reference was https://codedump.io/share/UJieoRlppEoJ/1/cannot-load-system-cursor-copydrop32x32-exception-in-java-on-centos-7

[Stefan van der Linden]

Hi Rolling, thank you for looking into the answer. This seems to work, although R2018B also seems to include a fixed Java runtime itself. All problems are fixed now anyway!

[Veethahavya Kootanoor Sheshadrivasan]

Hi Rolling.

I have applied your fix but the problem still persists for me.

Could you please help?

Also how do I generate a log file?

I tried to run matlab -desktop logfile test.log. But that did not create a log or I couldn't find it (although I performed a systemwide search).

Thanks in advance!

Answer 2

[Rolling Osure]

Found out something interesting. Starting matlab over SSH with X forwarding is successful!

ssh -X matlabhost
./matlab