The disable button on the Customer Free Text Invoice is disabled for a user which has the CustFreeInvoiceMaintain privilege assigned.
This situation only occurs in Ax2012 as Ax2012R2 has made a change to the CustFreeInvoiceListPage entry point within the CustFreeInvoiceMaintain privilege of setting the Access Level to delete from read.
In Ax2012 open a developer workspace
– Open the AOT
– Navigate to Security – Privileges – CustFreeInvoiceMaintain
– Expand CustFreeInvoiceMaintain, select Entry Points – CustFreeInvoiceListPage
In the properties change the Access Level from Read to Delete