Printing Mid-Air On First Layer
The Wrong Firmware
Make sure you have the correct firmware installed on your Altair V3. If the Z height doesn't read somewhere between 275.00 - 340.00, after the Calibration Routine is complete, you will need to re-install the firmware from the Support Center.
Calibration Failure may be occurring, check to make sure it is working properly.
Wrong Simplify 3D .FFF Imported
Make Sure you are using the Correct .FFF and that you imported it from Here.