I have over the wire update with Flash swap generally working on a K64.
If my process encounters a problem, I am unclear on what the most appropriate steps are to invalidate the process properly, such that I can continue operation with existing code, and still have the option of trying to reflash later. I do not find that AN4533 gives any useful suggestions on this.
Should I simply erase the whole block of flash on which I was working?
In case of an error condition situation when using the SWAP system, indeed you can simply erase the corrupted flash block and reprogram the firmware again. Please see a similar discussion in the next thread: