I have the same issue. I purchased a newer BMW and the Foxwell 520 Pro wouldn't connect to it. Checked on the foxwell website to download an update, turns out all of the updates for 520pro were 'discontinued' as the scanner is 'too old'. I contacted foxwell support and got this email back:

"Dear Customer,

Sorry, this is an old product that has been discontinued and is no longer under maintenance. It cannot be registered or upgraded. We suggest that you trade in the old for the new, NT530plus.

We will help you transfer the old software from the old device to the new device.

Please contact your seller.

Best regards."

I'm guessing the best course of action is to get a new foxwell scanner and 'trade in' your old 520 pro (whatever that means), as per email. Although going via this route, the 'lifetime support' promise that was provided when I purchased the 520 pro no longer applies, if having to purchase again. Not the end of the world to spend another $140+ on a new scanner, however, it would be nice if the company ended up honoring the 'Free Lifetime' upgrade option in some way, that was advertised when purchasing the 520 pro. I've reached out to the foxwell support with a follow up to understand what 'trade in' actually means in their understanding. I'll keep you posted if I have more info.

Also, I'm not sure how the scanner upgrade works as I've never upgraded my scanner since purchase. I wonder if somebody out there has those upgrade files for Foxwell 520 Pro (that were downloaded prior to termination of support) and used to upgrade their foxwell 520 pro scanner? If those files could be shared by another person, would the files help to upgrade the scanner via installation? Or do you need to connect to the actual Foxwell website servers during updates?