Emergency files, also known as emergency restore files or factory reset files, are a set of files that can be used to restore a Lumia 650 device to its factory settings in case of a critical failure or when the device becomes unresponsive. These files contain the necessary data to recover the device's operating system, settings, and built-in apps.
for the international Lumia 650) and Product Code to find matching FFU and emergency files. Proto Beta Test lumia 650 emergency files full
Using a third-party tool, such as the Windows Phone Recovery Tool, can help resolve the issue: Emergency files, also known as emergency restore files