Why I get Java error when I close Matlab in ubuntu

Each time when I close Matlab in ubuntu, A Java exception will appear in terminal

Exception in thread "Thread-7": 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)

[Alexander Kristensen]

I get the same error using MATLAB18b on Ubuntu 18.10

Did you find a solution?

---------- UPDATE

found out installing this library removed the error message:

https://se.mathworks.com/support/bugreports/details/1885601

It also solved my issues trying to enter the add-on manager.