I use a custom controlmap.txt. I have edited it several times, using both Notepad (text editor that ships with Windows) and Notepad++ (freeware advanced-formatting text editor normally used for coding text, i.e. xml).   Today, I encountered this warning on a Controlmap mod on the Skyrim LE Nexus: "Do not modify controlmap.txt in Windows Notepad. This will break it. Notepad does not have the proper encoding for the file. I recommend using a text editor that has automatic encoding,