Unable to install add-on

First when i tried adding a package(simscape) in MATLAB R2019a, error "unable to access /usr/local/MATLAB/R2019a" came. Then I chmod 777 the folder. Now I can proceed a few steps till the download screen when it downloads upto 40% and fails. This is the error in the terminal.

Exception in thread "Thread-12": java.lang.NullPointerException
	at com.teamdev.jxbrowser.chromium.internal.ipc.IPC.c(Unknown Source)
	at com.teamdev.jxbrowser.chromium.internal.ipc.IPC.b(Unknown Source)
	at com.teamdev.jxbrowser.chromium.internal.ipc.IPC.a(Unknown Source)
	at com.teamdev.jxbrowser.chromium.internal.ipc.b.run(Unknown Source)
	at java.lang.Thread.run(Thread.java:748)

[John Bushnell]

I am running Matlab R2019a on Ubuntu 18.04 with mate desktop. I am also accessing the machine remotely using x2go. Whenever I exit out of the Matlab GUI I get this exact same error message in the terminal where I started matlab in the remote desktop, every single time. So it seems to happen during the normal shutdown of the matlab session. I see the same error in both Windows and Linux x2go clients.

I just tested this directly on the server, and it shows the same error on exit.

My guess would be that this is not the cause of your Matlab session dying, but just an error it throws when it exits, just like I am seeing here.

Answer 1

[Shivam Kumar Singh]

To install new toolboxes, rerun the MATLAB installer to add any additional products not currently included in your installation..

To download the MATLAB installer, please follow the steps below:

• Go to the MathWorks downloads page: https://www.mathworks.com/downloads/
• Click on the blue button for the latest release or on the link beneath for any other release.
• Log in to your MathWorks Account if you are not already logged in.
• If you clicked on the link to download any other release, a list with older available releases will be displayed on the right. Click on the desired release.
• Select the operating system that you are using.
• The download will begin after you select your operating system.

Before running the MATLAB installer to install an additional toolbox, please keep in mind:

• Toolboxes must match the release of MATLAB they are installed into, e.g. you cannot install a toolbox for MATLAB R2019b into MATLAB R2019a.
• MATLAB must be closed in order to run the installer.
• The MATLAB installer will install new toolboxes in the default MATLAB installation folder. If you installed MATLAB somewhere other than the default folder, you will need to select the folder where MATLAB is installed when prompted for the MATLAB installation location.
• During installation, you may be prompted to overwrite any existing products. If prompted, opt to skip installation of any existing products.
• After installation, the activation process will begin. You need to activate your product in order to use them.

[XIYANA VEROSKA]

It worked for macos ventura, macbook pro m2

[dongha park]

I had a similar problem that MATLAB keep fails to install the add-on. well this solution works! thanks a lot