I am upgrading to a new computer soon and I spent a lot of time creating a custom Plug-In menu set in the Plug-In Manager, I’d like to make sure I take that file with me to the new computer, but I can’t seem to find it. Does anyone know where Steinberg hides this file? Thanks.
They sneakily hid it in the preferences folder and confusingly called it PlugInManager.xml 
To be fair, Windows does hide it unless you choose to show system files and folders in folder options but you can always access from the Start Menu/Cubase/Application Data.
Thanks so much, saved me a few hours of recreating my plugin list, really appreciate it.