I am using a custom PKCS#11 dynamic library and a hardware token to sign a document in Adobe Acrobat 10. I encountered this error when I used the Standard Text as the Appearance of the Signature.
Creation of this signature could not be completed. Unknown error Support Information: CDSHandler-657
If I use a custom appearance, the signing is successful.
Do I need to set anything else before signing the document? Everything works fine on Adobe Acrobat 11. I am using a Mac OS X 10.9 machine. The same error is encountered in Windows 7.
Is this a known issue in Adobe Acrobat 10?
Try updating the software, first? PKCS12 is the latest one.
Also-- you have to make sure you have a digital ID stored in the computer (or through a server), or you can create one.