Error on startup : Cannot locate or initialize class com/mathwo​rks/jmi/Op​aqueJavaIn​terface.

I am on Manjaro Linux and I installed Matlab R2024b.

When trying to start Matlab, I get the following error :

Cannot locate or initialize class com/mathworks/jmi/OpaqueJavaInterface.
java.lang.NoClassDefFoundError: com/mathworks/jmi/OpaqueJavaInterface
Caused by: java.lang.ClassNotFoundException: com.mathworks.jmi.OpaqueJavaInterface
        at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
        at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)

I tried changing the java version used by using matlab_jenv to switch to the default version on my machine, 1.7. It did not make a difference. Command:

sudo ./matlab_jenv -allusers system                                                           1 ✘ 

Result:  1 ✘

JavaEnvironment with properties 
Version       : openjdk version "17.0.13" 2024-10-15
                OpenJDK Runtime Environment (build 17.0.13+11)
                OpenJDK 64-Bit Server VM (build 17.0.13+11, mixed mode, sharing)
Home          : /usr/lib/jvm/java-17-openjdk 
Library       : /usr/lib/jvm/java-17-openjdk/lib/server/libjvm.so
Configuration : system 

I tried creating a java.opts file as suggested here. It did not make a difference.

I tried uninstalling and reinstalling matlab. It did not make a difference.

I had never set a MATLAB_JAVA variable, setting/unsetting it does not make a difference.

Any advice appreciated.

Answer 1

[Grace Kepler]

Please see the Accepted Answer on this MATLAB Answer for help on this issue.

Why does MATLAB crash at startup with the error "Cannot locate com/mathwo​rks/jmi/Op​aqueJavaIn​terface class"?

Answer 2

[Steph Bredenhann]

I have the same problem, installed Matlab R2024b on Ubuntu 24.04 LTS.

Answer 3

[Johannes]

Same problem, running macOS 15.1.1. and Matlab R2024b. Java Runtime 11 is installed as per the manual of Matlab. Setting MATLAB_JAVA variable does nothing.

Please advise.

Answer 4

[Joonatan]

I'm having the exact same issue. Did any of you find a solution? I have a fresh install of Linux Mint 22 Cinnamon and Matlab R2024b. I tried reinstalling Matlab, same issue. Exact error:

Cannot locate or initialize class com/mathworks/jmi/OpaqueJavaInterface.
java.lang.NoClassDefFoundError: com/mathworks/jmi/OpaqueJavaInterface
Caused by: java.lang.ClassNotFoundException: com.mathworks.jmi.OpaqueJavaInterface
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

[Joonatan]

I solved this by installing R2023b. Runs with no issues.

[Navaneeth]

Try this

sudo /usr/local/MATLAB/R2024b/bin/glnxa64/registerWithOS.sh

It solved mine(debian), but i don't know how :)

[kh]

Navaneeth's advice was helpful. I installed R2024a on ubuntu20.04.

Please try:

sudo /usr/local/MATLAB/R2024b/bin/glnxa64/registerWithOS.sh