In the Program directory ( C:Program Files (x86)Mozilla Firefox for
example) put a “config.js” with:

//
try {
Components.utils.import(“resource://gre/modules/addons/XPIProvider.jsm”,
{})
.eval(“SIGNED_TYPES.clear()”);
}
catch(ex) {}

Then, in “C:Program Files (x86)Mozilla Firefoxdefaultspref” put a
config-pref.js with

pref(“general.config.obscure_value”,
0);
pref(“general.config.filename”, “config.js”);