Unity package manager starting server stuck

Situation description

The author is windows pc, Multiple versions are installed unity, There's never been a problem . Suddenly there is a version （2019.2.8f1） Of unity It won't start . Try the new project 、 And reinstall this version of unity, Can't solve . But several other versions unity No problem .
The specific performance is that it gets stuck after startup Starting Server… Interface

After a while , The error reporting page pops up ：

Common solutions

The author goes to heaven and earth to find solutions , Most of the solutions are as follows ：
a. Disable firewall
b. modify hosts file
Add a row ：127.0.0.1 localhost（hosts File directory ：C:\Windows\System32\drivers\etc\hosts）
And then in cmd Execution in command ：setx UNITY_NOPROXY localhost,127.0.0.1
c. In the system environment variables increase key/value term
key by UNITY_NOPROXY,value by localhost,127.0.0.1
…
I tried , It's no use

Solutions for the author

To configure 1

open The Internet and Internet

Click on the image above Network and Sharing Center Button , The interface below pops up .

Click on Internet Options , Click again Connect --> LAN settings

Set as shown in the figure above

To configure 2

Search for agent , Open the following page , And set as shown in the red circle ：

To configure 3

In the system environment variable , Delete all HTTP_PROXY perhaps HTTPS_PROXY The item

This configuration , Solve the problem smoothly （ Reference documents ）