"There was an error with this field's customized event" error when you upgrade to Microsoft Dynamics CRM 2011 and then open forms
This article provides a resolution for the problem where you receive an error message after you upgrade to Microsoft Dynamics CRM 2011.
Applies to: Microsoft Dynamics CRM 2011
Original KB number: 2494575
Symptoms
After you upgrade to Microsoft Dynamics CRM 2011 and then open forms of certain entities, you receive an error message that resembles the following:
There was an error with this field's customized event.
Field:window
Event:onload
Error: 'crmForm.all.tab2Tab.style' is null or not an object.
Cause
This issue can occur if you use unsupported JScript customizations in Microsoft Dynamics CRM 4.0 that break the form loads in Microsoft Dynamics CRM 2011. Unsupported JScript methods include hiding controls, tabs, or menu items.
Resolution
To resolve this issue, remove these kinds of customizations and instead use supported methods. The Microsoft Dynamics CRM SDK has a list of new capabilities that replace unsupported methods. Refer to the SDK topic Upgrade Scripts to Microsoft CRM 2011 for more information about how to replace the old, unsupported methods with the new, supported methods.
More information
To download the Microsoft Dynamics CRM 2011 SDK on the Microsoft Developer Network (MSDN), see Development for Microsoft Dynamics CRM 2015 (CRM SDK).
Support assistance with unsupported customizations may be considered billable.