Following the tutorial, the following error occurred when the installation was completed:

Solution:
Copy the crack tool MATLAB_R2018b_Linux64_Crack directory /home/username/mnt/LINUX/MATLAB/R2018b/bin/glnxa64/matlab_startup_plugins/lmgrimpl/ libmwlmgrimpl.so Copy to the installation directory /usr/local/MATLAB/R2018b/bin/glnxa64/matlab_startup_plugins/lmgrimpl/libmwlmgrimpl.so

Just restart