IE crashes on form navigate function MSCRM 2015 online

Hi All,

We recently upgraded to Update1 of CRM 2015 online. We have a custom entity having 3 forms which are programmatically changed according to a type optionset value selected by user. There is a javascript function attached on change of the type optionset where navigate() method of Xrm.Page.ui.formSelector.items collections. whenever user is changing the type optionset value getting the crm standard popup to save the unsaved changes, on clicking ok for this popup getting IE crash popup as shown below -

Any help is highly appreciated.

Thanks,

Sanchita