Windows and Linux are two different animals.
FTA receivers are based on Linux and not Windows. It may be possible to find something that runs in Windows to unpack UBIFS, but I don't know of anything.
Linux tools or applications exist to unpack UBIFS, so you will probably need to be on a Linux machine to do the task you want.
You might get the receiver to unpack it for you by placing the file system you need unpacked on a usb drive and inserting it in the receiver, but I do not know the tools or telnet commands for doing that. Maybe someone else does???
Tool for viewing and extracting files from an UBIFS image - nlitsme/ubidump
github.com