How Can I remove the Effective End date and re-enable a Tax code setup in the Tax Manager?

Hi Oracle experts,

A Tax code was end-dated.  The AP user was unaware that AR staff were using that tax code to create Auto-invoices from Copying past invoices.

Now when they copy an invoice from the past, they get an error, as the tax has been disabled and end-dated. 

Is there a way to re-enable and remove the end-date for this tax code in Tax Manager?

The Effective To Date is greyed out...

Thanks for any help in this matter.  Greatly appreciated.

Niketa