V-Ray Frame Buffer is missing in 3ds Max | How to fix it

When rendering a scene in 3ds Max the Rendered Frame Window (or V-Ray Frame Buffer) is missing or has suddenly disappeared. How to fix it?

#1. Go to C:\Users\User Name-\AppData\Local\Autodesk\3dsMax\20xx – 64bit\ENU\en-US\plugcfg

#2. Open the vrayvfbuser.ini file.

#3. Set the X and Y positions =1,1

#4. Reset the 3ds Max preferences to their defaults.

Source: https://knowledge.autodesk.com/support/3ds-max