Cloud Application Studio 1708 error Business Object does not exist in project

In Cloud Application Studio 1708,

I have added a business object, to my solution and activated succesfully.

But when I try to add Script Files it gives "Business Object does not exist in solution ...... (in development)" error. (Actually it exists and activated.)

Strangely, even after giving this error, it writes as "Script Files added successfully". But doesn't add it in reality.

I also tried to create Query from this BO. It says "Check failed".
But if I check the full solution it checks successfully.

Please help me solve this issue.

I have stucked and can't do further development.