In Iron Speed Designer V3.0, the CustomBasePage class was renamed to BaseApplicationPage. As a result, the file name was changed from CustomBasePage.safe.aspx.vb (cs) to BaseApplicationPage.vb (cs).
During migration, no changes will be made to the control names in your “safe” class files. By policy, Iron Speed Designer does not modify your safe class files.
You must manually move any existing code customizations in the CustomBasePage class to the new BaseApplicationPage class in BaseApplicationPage.vb (cs).