(NS_ERROR_NOT_IMPLEMENTED) ERROR CONSOLE FIREFOX

[Exception..."Component returned failure code: 0x80004001 (NS_ERROR_NOT_IMPLEMENTED) [nsIRequest.name]" nresult: " 0x80004001 (NS_ERROR_NOT_IMPLEMENTED)".
File location : program files > mozilla firefox >components>nsLoginManager.js.

uncaught exception: [Exception... "Component returned failure code: 0x80004002 (NS_NOINTERFACE) [nsIInterfaceRequestor.getInterface]" nsresult: "0x8000402" (NS_NOINTERFACE)" location:"JS Frame:: chrome://speedbitvideodownloader/content/tb.js ::anonymous :: 7426" data:no]