1. The last agent used was not cancelled. If you surf the Internet without canceling the proxy, you may not be able to connect to the proxy, so you cannot open any web pages.
2. The security level of firewall is too high. If the security level is too high, the firewall will prevent the transmission of normal data. Please select a typical setting.
3. Browser setup problems, such as setting too high a security level and running abnormal add-ins, are common. Users are advised to restore typical settings and disable problematic add-ins.
4.DNS configuration is incorrect.