Matlab 2018b freezes on Help command in MacOS 10.13 (High Sierra)

I just installed Matlab 2018b on a mid-2010 Mac running 10.13.6 (High Sierra). The program stops responding when I give Help commands or go into Documentation. The Mac itself continues to work as I can move my mouse and was able to take a screen shot of the frozen Matlab window. I was also careful to close all other applications while running Matlab except Acctivity Monitor. Memory usage and CPU usage are 25% and <10% respectively. Anyone know of solutions?

Thanks