Check whether the driver of the digital certificate is installed successfully. If the business license of Guangdong Merchants Corporation can't be signed, you can first check whether the driver of the digital certificate is successfully installed. If there is any problem with the signature of the business license, you need to refer to the valid identity information to check whether it is correct. You can also check whether the business license number is used for registration on the website of the Administration for Industry and Commerce through the business license number. In this case, if I still can't sign, I must refer to my real identity information to check with the Administration for Industry and Commerce to see if there are any related problems.