Place the patch-edid.rb file into the /Users/ directory.This script works by setting up a profile for your specific monitor, and having it be forced to be RGB, if you connect it to another model monitor with the same issue, this process will need to be repeated for that monitor as well. Some people with panels like mine will get pink, others likely get no signal recognized. The reason it is having an issue, is after the update, the signal being sent is YCbCr instead of RGB like your monitors are expecting. you will have to switch back to the working screen for the steps 6-15 After doing so, connect the nonworking screen, start the computer, and log in remotely, then follow the steps 1-5 below. For those of you without working screens, I suggest finding a screen that does work temporarily, and installing Teamviewer, or some other free program to remotely log into your machine. I think it might apply to your issue as well.

I fixed my full time pink screen issue, here is the solution. Maybe this might point you in the right direction.

Viewsonic drivers mac smh