Can't send email templates to Leads and Contacts

Can't send email templates to Leads and Contacts

I recently changed my default "from" email address.  When I try to send a public email template to a Lead or Contact I can no longer see the picklist of available templates to select.  All I see is "None," and when I click the drop-down arrow, there is no picklist of my templates.  I was previously able to do this.
 
Please advise - thanks.