SAP upgrade problem: We are performing Support Pack updates on our ECC6/EHP5 system. However, GuiXT scripts are not being executed following the updates.

My first guess is a configuration or license key problem. Can you please display the GuiXT protocol with View->Protocol in GuiXT window and look for error messages?  If your SAP system name has changed you need a new GuiXT license key which we can send you free of charge.