Hi All,
Recently i have migrated the Ext.net version from 2.5 to 4.5.1 . We have multiple tab panel with single save button. After clicking on Save button javascript function will invoked. Earlier this functionality working fine with 2.5.
But now with 4.51 its not working.

form.submit({
success: function (form, action) {
//some functionality.
}});

Getting below error.
Uncaught TypeError: Cannot convert undefined or null to object
at Function.keys (<anonymous>)
at constructor.upload (ext.axd?v=4.5.1:11207)
at constructor.start (ext.axd?v=4.5.1:15898)
at constructor.request (ext.axd?v=4.5.1:16184)
at constructor.doSubmit (ext.axd?v=4.5.1:112488)
at constructor.run (ext.axd?v=4.5.1:112461)
at ext.axd?v=4.5.1:4545
at Object.elevate (ext.axd?v=4.5.1:1919)
at timerFn (ext.axd?v=4.5.1:4640)