I had that same issue with a flashing yellow light and I thought it was the calibration and I calibrated about 3-5 time. That wasn't it, its also has nothing to do with the firmware or battery. Yellow flash light indicate that there is low light in the area. If you have the light on where your drone can see clearly and still your drone is not flying then check the propellers. In the manual on page 9 , you will see 2 with lines on them they need to vertically across from each rather then next to each so that the drone has a proper balance. You will see a marking on the propellers that need to match the marking on where the propellers need to be place. Once that done your drone will be able to fly well without an issue.
Hope this helped.