Hello,
Difficult to be totally affirmative because of the level of details.
Add a pull-up resistor of 5-10k Ohm between BGND and VDD pins on the BDM connector of your board.
This particularly more important on higher speed crystal with longer PCB tracks (added capacitance) to allow the background line to get back to Vdd fast enough when not driven.
If this does not work, please come back with more details.
If this does, please also tell us to help other users.
Before TBDML, I was using USBMULTILINK on S12(X) daily without trouble.
Alban.