RNS510 Firmware downgrade

[GerardR]

Hi guys,
looking for some advice.
Does anyone know of a way to downgrade the firmware without having access to the secret menu or vcds?
version being 6276 to 5238.

Thanks in advance,
Gerard

[FJ Steve]

@kamold
Mate...would you be so kind as to review this SWL Error code, and then advise if it should be safe to downgrade to FW5238. Or, are there more sinister issues involved with his code?

Imgur: The magic of the Internet

User @GerardR has come across this issue after noting there was no navigation file on his RNS510 (refer to his 'other' thread.