The cause:

For the two reasons listed below, a form control could not be focusable after validation is initiated:

-As shown in the business logic’s present context, the field is irrelevant. The appropriate control should either be disabled in such a case, deleted from the DOM, or not tagged with the required at that time.
-By hitting the ENTER key on an input, a user may trigger premature validation. Or a user may click on a button or input control on a form that has an incorrect type attribute definition. The default value of a button’s type property is submit, thus if the type attribute is not changed to button, Chrome runs a validation each time the button is pressed.

Solution: If your page has a button that performs something other than submit or reset, always consider doing the following to fix the error “an invalid form control with name=” is not focusable”:

<button type="button">