1. The certificate has expired: If the digital certificate you are using has expired, the system will not be able to verify your identity. At this point, you need to reapply or update the digital certificate.
2. Certificate mismatch: If the digital certificate you use does not match the current system or document, the system will not be able to verify your identity information. At this time, it is necessary to confirm whether the certificate is correct and choose the correct certificate to sign.
3. Signature file is tampered with: If your signature file or signature content is tampered with, the system will not be able to verify your identity information. At this time, it is necessary to re-sign the file to ensure that the signed file and signature content have not been tampered with.
4. Incorrect computer time: If your computer time is inaccurate, the system cannot verify your identity information. At this time, it is necessary to adjust the computer time or synchronize the network time. If you encounter the problem that you can't verify your identity information, you can try to reapply or update your digital certificate, and make sure that the signature file and signature content are correct. If the problem persists, you can contact adobe customer service or related technical support personnel for help.