After installing LS beta 4.0 and restarting. I could not get the Network Monitor to open.
After testing all of the modes, I decided I would kill the process and restart. Upon attempting to quit the process Little Snitch Help and Little Snitch Agent the Network Monitor appeared.
OS: 10.12.5 (16F73)
Mac Pro (Late 2013)
CPU: 3.5 GHz 6-Core Intel Xeon E5
RAM: 32 GB 1866 MHz DDR3