I am having problems with USB Virtual com port .
I made a new hardware which is a replica of Xmega256a4bu demo board with one minor change is USB VBUS connection.
I am not using USB VBUS and left it floating, I connected on board power supply to the ESD protecting device.
When I am trying to communicate with PC, My hardware sometime doesn't work properly whereas XMEGA256A3BU demo board always works.
Can anyone help me please ?