+ Add New is not working

I don't know why in creating invoices or any other modules with "+Add New" button is not responding, it is not responding to button click.

By the way my version is 2.0.18. Thank you.

Same issue. Just don't click. Language is russian, if it matter.

Try typing all of the new item in the entry field first THEN click the Add New. For example, while entering an invoice and you need to add a new Service, in the Service field type in part of the NEW service name and THEN click Add New. The field will now display "new" beside the service name. Once you have saved the invoice, the new service will be created.