Did i not release a 5.1.0 blogpost? Wow.
Anyway, here is 5.1.1 and it brings a good chunk of fixes for a lot of your issues! Yay!
NOTE: Make sure you fix your light count setting as instructed in the video, also CLEAN INSTALL the viewer, that means MANUALLY deleting everything in the Viewer folder and then installing the update, this gets rid of leftovers and ensures you get the same Viewer as everyone else. (Looking at you people that still have unsupported language files)