I have a custom Validator for dates (probably won't need it with Dojo validation, but it showed up this error). It calls:
FormComponentContributorContext.addSubmitHandler() with a function call. This method in the Impl class adds a page initialization script that calls:
which is deprecated. Either the method should be updated to use old validation code with the new framework or mark the method as deprecated and indicate that developers should rewrite their code, following the examples in the org.apache.tapestry.form.validator package.