1) Make sure you are using the most recent version of software by clicking on HELP and "Check for Updates" (or go to K-Manager), after updating go back to help and click on HELP and "Update USB Drivers" then follow the instructions.  See if the problem persists.

2) With the ECU plugged in to the car, the USB cable plugged into the ECU and the Laptop and the ignition switch in the ON position - Does the K-Manager software say Ignition On and Online?  If it does not, verify that all the connections have been made, and verify the Ground in the engine bay (K-Series Engine Ground).

3) If you are having trouble uploading a calibration or with an existing calibration in the ecu, try going to Online, Tools, and click on Clear Security, then try uploading a new calibration.  You should also only use the Download calibration function as a last resort if you have lost the calibration stored on your laptop.

4) If you are having Datalogging issues, check to make sure your USB cable is firmly attached to the ecu and the laptop.  Verify the Ground in the engine bay (K-Series Engine Ground).  Verify you are using resistor spark plugs (K-Series Spark Plugs).  Check to make sure the K-Pro board inside the ECU is firmly attached, but be careful to ensure that the screw is not so tight as to make the board to bow under the screw.  Make sure you have the latest version of software and you have uploaded the calibration using that version of software.

5) If you are still having trouble with the K-Pro try using a different laptop, and try the substitution method (try the ecu in another vehicle, try swapping the K-Pro board with a known good board...etc).