As per my knowledge this issue is caused due to some missing shared libraries required for proper functioning of the jxbrowser.
The following steps should get you started to identifying the issue:
Finding the missing libraries:
Execute the following command in the system terminal
ldd ~/.matlab/R2018b/HtmlPanel/glnxa64/chromium/jxbrowser-chromium | grep -i found
The output will list out the missing libraries as follows:
libgconf-2.so.4 => not found
Installing the missing libraries:
You can install the missing libraries via apt by executing the following command:
sudo apt install libgconf-2-4
Please note that you might have to install a different package from apt depending on which libraries are missing.
Please refer to the following MATLAB Answer for more information: