1, authentication server problem, so everyone can't use it. Solution: use someone else's computer to see if you can log in;

2, network cable port problem, solution: you can see whether your network cable is plugged in, whether there is a problem with the network cable, if there is a problem, there will be a red cross icon on a small computer in the lower right corner of the computer;

3, account problem, solution: contact your network administrator to open or reset your account;

4, the access layer switch problem, solution: directly find the network management to solve it for you, you can't solve this yourself.

I hope I can help you.