Connecting ATMega2560 chip to FTDI chip to PC

In what sense? Not able to upload? Or a loaded sketch can't communicate with the PC?

Did you design your own board? If so, schematic please.

Your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with (nor for advise on) your project :wink: See About the IDE 1.x category.