win7：
8080端口已经被其他应用使用，比如nixxxxxxxxxxxxx
When I had an error Access Error: 404 -- Not Found I fixed it by doing the following:
Open command prompt and type "netstat -aon" (without the quotes)
Search for port 8080 and look at its PID number/code.
Open Task Manager (CTRL+ALT+DELETE), go to Services tab, and find the service with the exact PID number. Then right click it and stop the process.
以上来自stackoverflow……
鄙人研究了半小时，才把这个破问题解决，真是蛋疼……