Hey Zhengdong,
I am not sure that I can help you in this case but,
Just giving a suggestion :),
If you are not getting any solutions for your problem,
You can always reach @support.mendix.com and raise a ticket for your issue,
Attach the screenshot of the error you are getting, and then you will get a suitable solution.
Hope it helps!
Is this with every action you take?
I will get such errors only if I set a color of an action to default color.
Have you tried with another (older) studio pro version?