Here are my notes on forced upgrade.
flash.bin recovery is done like this.
Place a copy of the unpacked software (the .bin file) on a USB stick and rename it "flash.bin"
With the USB in the unit, power on while repeat pressing "Menu" on the remote.
The unit should reload the software.
Also other users say that you must use a USB stick, not a card holder etc and that stick must be 32Gb or under.
Use the rear USB port on units that have two ports.
I have had units that will not recover.
Try using the same software as was in the unit when it crashed, not the new update software.
You must use the correct software, ie that for the V7HD for the V7HD etc, not software for any other freesat units.
Try even older software as the file for flash.bin.
Look at the LED in the USB stick. When the TV shows the message "USB Upgrade, do not turn off" you should see the LED on the USB flash as the file is loaded.
The USB LED should also flash a few times as the unit first powers on and looks at it.
Also users have said to use the rear USB port for this on V8 units.
New information: Users are reporting that naming the file "Flash.bin" with a capital has worked where "flash.bin" has not. This is with the Nova units mostly.
Dishes; 3x3m, 2.4m and 4.1m, 10+ ku, 2 movers, USARLS. V8 Combo, Pro, V8 Golden, Nova V8Pro2, GTC, Super.V7HDs, Combo and V7s V7Plus Finder, Finder-Meter V8X / UHD V7Pro GTCombo. Sats 100.5E to 177W. I'm a Sat hobbyist who helps out.