Undefined variable errors - strange situation

I have a problem with existing project. I get the message: ErrorException (E_ERROR) Undefined variable: errors

and in my code where error occur is: @if (count($errors) > 0)

I was try to install new project with same plugins and features and on new project I don't have that problem and error exception. Environment on both projects are: LEMP, PHP: 7.1.1 Laravel: 5.5

What can be that error?

via Chebli Mohamed