Expected behavior Open modal Actual behavior Webpage crashes when modal is opened. With example code too. Resources (screenshots, code snippets etc.)

export default class TestPage extends Component {
state = {
    modal: false
}

toggle = () => {
    this.setState({
        modal: !this.state.modal
    });
}
render() {
    return (
        <MDBContainer className={"pt-5 mt-5"}>
            <MDBBtn onClick={this.toggle}>Modal</MDBBtn>
            <MDBModal isOpen={this.state.modal} toggle={this.toggle}>
                <MDBModalHeader toggle={this.toggle}>MDBModal title</MDBModalHeader>
                <MDBModalBody>
                    (...)
                </MDBModalBody>
                <MDBModalFooter>
                    <MDBBtn color="secondary" onClick={this.toggle}>Close</MDBBtn>
                    <MDBBtn color="primary">Save changes</MDBBtn>
                </MDBModalFooter>
            </MDBModal>
        </MDBContainer>
    );
}

}