[Annihilator]

I've been getting this error lately and I've got no idea what's wrong
Error and translation examples:

PHP Code:

Ignoring translation to invalid language "#format" on line 


PHP Code:

    "killed"
    {
        "#format"    "{1:N},{2:N}"
        "en"        "{1} killed {2}"
    } 


Any idea what could've coused it?