Another three year delay for the F-35

Aviation week
"....Another three-year slip to initial operational test and evaluation, the culmination of system development and demonstration, which now is due to be complete in 2019 – the target date is February but the threshold date is October."

".....it appears that the main culprit is software and hardware, mainly in terms of the integration functions – sensor fusion and emission control – that take place in the fighter’s main processor banks."