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

238 views (last 30 days)
When I start MATLAB, I receive a "Fatal Error On Startup" window that says:
Cannot locate com/mathworks/jmi/OpaqueJavaInterface class
When I click the OK button, the window disappears and MATLAB does not start.

Accepted Answer

MathWorks Support Team
MathWorks Support Team on 19 May 2023
Edited: MathWorks Support Team on 19 May 2023
This error may occur if you have set a MATLAB_JAVA environment variable for a previous version of MATLAB. If this variable is set, you will need to unset it in order to run MATLAB. For more information on MATLAB_JAVA, see one of the following articles:
This error can also be caused by a java.opts file on the MATLAB path. If you are using Windows and you have checked your path for java.opts files, but you are still receiving this error, make sure the "Start in" field in your shortcut is set to a directory that doesn't contain a java.opts file.
If MATLAB_JAVA is not set and java.opts is not present, then your MATLAB installation may be corrupt. Uninstall and reinstall MATLAB to repair your MATLAB installation. An installation of a different release of MATLAB may also work.
  2 Comments
Kouichi C. Nakamura
Kouichi C. Nakamura on 28 Nov 2021
Edited: Kouichi C. Nakamura on 28 Nov 2021
I'm getting the same error
Cannot locate or initialize class com/mathworks/jmi/OpaqueJavaInterface.
on macOS 12.0.1. The link mentioned above:
is about how to change JVM. But it is not kind enough tell how to unset. Also, it says:
> This article applies only to MATLAB launched from a shell window or modified shortcut as both of these methods set-up the MATLAB_JAVA variable. Clicking on the regular MATLAB icon will not use the new Java.
My root problem is that I cannot lanch MATLAB by clicking. While investigating this issue, I found an article about launching MATLAB from Terminal, and I received the error above.
Can you elaborate a bit more what I should do next?
Kouichi C. Nakamura
Kouichi C. Nakamura on 19 Dec 2021
Following the guide below, I tried Regenerate Preferences, and Start MATLAB from the Installation Folder with no avail. I deleted MATLAB and reinstalled it, and it launched eventually.

Sign in to comment.

More Answers (0)

Categories

Find more on Startup and Shutdown in Help Center and File Exchange

Tags

No tags entered yet.

Products

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!