Prevent save OnSave 2015

Hi,

I am using Xrm.Page.context.getEventArgs().preventDefault();

to prevent save for validations on 'OnSave' event.

But an error is being thrown after it prevents save.

Objectdoesn'tsupportpropertyormethod'getEventArgs'

It actually prevents save like it shoule but this error is being thrown inconsistently. I am using CRM 2015 Onpremise.

Has this been changed in 2015? Someone please answer me. Thanks.