I've had a problem programming with a Multilink Universal connected to a K40 processor.
Using CW10.4 (and later CW10.6) I have 14 identical boards that all programmed and debugged properly.
Over time 4 of the boards would no longer open in the debugger.
I discovered that I could program those board with the Flash Programmer utility in CW10.X.
However, during the Flash write there was no Verify on those boards. The other boards performed a Verify stage after each Program stage.
I'm not sure what changed for those 4 boards but they appear to have lost the ability to read from the JTAG port.
Is there some kind of security bit in the K40 that might have been set inadvertently?