Problems in the system background. The abnormal call interface of electronic tax bureau is a problem in the background of the system. You need to contact the after-sales customer service and let the customer service handle it remotely. When there is an abnormality, you can first check whether the green light of the tax control panel is on. If there is no light, you can pull out the tax control panel first and then insert it again, which can solve some problems of poor contact.