From this related forum post:
as per the below screenshot of the PLECS User Manual on this topic, you can enter the body diode Err losses in the left half plane (negative currents) of the Turn-off losses table:
From this related forum post:
as per the below screenshot of the PLECS User Manual on this topic, you can enter the body diode Err losses in the left half plane (negative currents) of the Turn-off losses table: