Where Idea puts “idea.exe.vmoptions”

If you follow the Idea help to change JVM options for Idea, they recommend that you select “Help -> Edit Custom VM Options”.

Unfortunately if you screw up this file, Idea won’t start, and the help does not tell you where the file actually is. For me it is here:

C:\Users\gsieling\.IdeaIC2016\idea.exe.vmoptions