The Command failed to execute error

I can not start “mission_start” after MP 1.3.75 . ( There is no problem 1.3.74 and below )
May be it is about “do action” button , because when i click preflight_calibration , i get same error message.


Am I the only one getting this error in the world?
I tried it on several different computers, I installed the beta version. But the simulation doesn’t work also it doesn’t work in auto mission .