1. "No user Certificates available" during digital signing
Fix: This issue will happen if you are not running your IE browser as Run as Admininstrator. You can always set this on IE(right cick->properties->advance->Run as Administrator
(Note: SAP DSC Active X control (sapsign.cab) is developed in VC++(microsoft platform) it will work only in IE browser -read my previous blog on DSC)
2. "Signing Error"
Fix: This issue will happen when you are running the Active X control(sapsign) for the first time or your Active X component is not able to access the private key from the token. This will happen commonly on Windows 7 + OS along with some token drivers. In such case change machine or contact your token providers for suitable drivers.
3. "Could not verify the Digital Signature"
Fix: If you are getting this error , you have not uploaded the root of the certificate used for digitally signing in the transaction STRUST. If you export the public key of the certificate and then upload to STRUST the verification process will succeed , but this is not recommended because you have to maintain large no of certificate in STRUST and this truncation is not designed to maintain large no of certificates.
4. Object not found" or "Done with errors" or No Active X POPUP for installation when you are trying install the ActiveX (sapsign.cab) for the first time
Fix: This means that your system don't have microsoft runtime Re-distributional library installed on your PC.Go to the Link and install it based on 32 or 64 bit OS
5. Dump error during signing if the signing process exceeds 1 minutes
Fix: Unfortunately SAP SRM digital signature signing has to be completed within 1 minute. This is is hardcoded in the program(sapsign) as 60 seconds. So if it a large documents it can result in dump error some times. So it would be your token password is ready before you start attaching documents(Don't run for password or don't use the print option in DSC control during signing) .If it results in dump, a lock will there in SM12 and you have delete this manually. or you have to provide a webdynpro program to release the lock to the portal users.
6. "acr_error" during Digital signing or Page crashes.
Fix: Enable the compatibility view option on IE and add your website name in compatibility view setting in IE.You can find the comapatability view setting in IE->Tools
You are also welcome to write your findings on Digital Signature.