Pay attention to check whether the free signature is installed incorrectly in the signing process, import the certificate and key into the signing certificate and key, and remember to choose the signature instead of the self-signature. If there are still problems, there are three possibilities: 1. When applying for a certificate, the serial number was entered incorrectly, and the certificate applied by others cannot be used by itself. 2. The software installation authority is high, and it needs to be cracked before installation. 3. The software has been signed by others, and you need a free signature to sign it.