MacOS – ‘unknown file attribute: i’ error on DefaultKeyBinding.dict file

I would like to swap some key bindings on macOS Sierra. I have used Karabiner so far but unfortunately it is no longer working on Sierra.

So I tried to use DefaultKeyBinding.dict, but after I set it, I found that all the keys except ones that I modified were no longer working (the typing isn't reflected). I tried source DefaultKeyBinding.dict and got the following error:

/Users/me/Library/KeyBindings/DefaultKeyBinding.dict:2: unknown file attribute: i
/Users/me/Library/KeyBindings/DefaultKeyBinding.dict:3: unknown file attribute: i

Here is my DefaultKeyBinding.dict file:

{
";" = ("insertText:", ":");
":" = ("insertText:", ";");
"'" = ("insertText:", '"');
'"' = ("insertText:", "'");
"\\" = ("insertText:", "\U007f");
"\U007f" = ("insertText:", "\\");
}

What is the meaning of the error and what is wrong with this dict file?