SyntaxError: ambiguous indirect export: default Error when importing my own class

I have written a validation class and want to include it in my VueJS 3 project. Unfortunately I get the following error: SyntaxError: ambiguous indirect export: default

This is my code:

// ..classes/formValidationClass.jsexport class FormValidator {...}// some vue file with a formimport FormValidation from "..classes/formValidationClass"export default {...}

What does this error mean and what do I have to do to correct the error?