1. Network connection problem: First, confirm whether the network connection is normal, and check whether the network settings, Wi-Fi connection or mobile data connection are normal. You can try to open other websites to determine whether it is a network problem.
2. Server problem: official website may have encountered server failure or maintenance, resulting in abnormal access.
3. Geographical restrictions: Official websites may be restricted in some regions or countries. It may be due to geographical restrictions, network shielding or policy restrictions.
4. Browser problems: Some specific browser settings or plug-ins may prevent access to websites.