PICkit3 unable connect to PIC18F using V5.15 while V4.05 is fine (mouchuanlin)

Hi,I am using MPLAB XIPE/IDE V5.15, cannot connect to device while v4.05 is fine.Have you seen this before? How to do the suggestion steps? ThxDick Connecting to MPLAB PICkit 3... Currently loaded firmware on PICkit 3 Firmware Suite Version.....01.55...