Digital signatures available for signing in ABBYY FineReader 15 are located in the Personal certificate store of a user account. All certificates that contain a Private Key are shown in the application. Make sure you have a Trusted Root Certificate for the signature you want to use.
To see the list of the certificates available in the MS certificate Personal Storage:
- Press Windows+R, type certmgr.msc and click OK;
- Open Personal > Certificates;
- Find the certificate you use for signing in FineReader 15;
- Right-click on it and select Open and make sure that the certificate is valid;
- Open the Certification Path tab and make sure that all certificates in the tree including the Trusted Root Certificate are valid.
After the document is signed with a valid signature, PDF-viewer may display it as invalid on a computer that does not have a Trusted Root Certificate which was used to sign the document.