I am trying to digitally sign an Excel spreadsheet. I can add the box, I can type my name at the X but when I click the 'Sign' button to complete the action I get an error message saying; "Your signature could not be added to the document. If your signature requires a smart card, ensure that your card reader is installed correctly" then can only click on the 'OK' icon and the dialogue box closes.

I had never gotten this error previously but now I cant sign any documents.

please follow the below link to add your digital signature:
http://office.microsoft.com/en-us/word-help/add-or-remove-a-digital-signature-in-office-files-HA010354308.aspx
If you can't figure it out, make sure you selected the proper certificate, when you see the 'sign' window, click 'change'->click 'here to view the certificate properties' .

please follow the below link to add your digital signature:
http://office.microsoft.com/en-us/word-help/add-or-remove-a-digital-signature-in-office-files-HA010354308.aspx
If you can't figure it out, make sure you selected the proper certificate, when you see the 'sign' window, click 'change'->click 'here to view the certificate properties' .

• Marked as answer by Tony Chen CHNMicrosoft contingent staff, Moderator 17 hours 52 minutes ago
• Unmarked as answer by Bill Gotsch 17 hours 33 minutes ago

I have tried this and it did not work.