The solution to the prompt "Please select a signed digital certificate" is as follows:

(1) Check whether the certificate is successfully connected to the computer.

(2) Check whether the certificate uses a USB extension cable. If so, it is recommended that you connect the certificate directly to the computer. Or replace the USB interface.

(3) After unplugging and inserting the certificate, restart the computer.

(4) Check whether the "Certificate Status" is "Running", "Available" or "Existing".

(5) Check whether the "Self-service registration status and attributes" in the digital certificate is available. If not, we will guide you to uncheck the checkbox from bottom to top, then click OK, and then select "Self-service registration status and attributes". Properties", click the check mark from top to bottom and select OK. (The new version of the driver ignores this item)

(6) If your system is 2000 or XP, please select "Services" under "Administrative Tools" in the "Control Panel" to check whether SMARTCARD is enabled. If it is not enabled, please enable it.

(7) Reinstall the driver and patches. If it still cannot be used, it is recommended that you reinstall the system or change the computer.

(8) It is recommended that you bring the certificate, card and valid documents to the certificate agency outlet for certificate recovery.