TFS TfsTeamProjectCollection 获取不到WorkItemStore

Uri tfsUri = new Uri("http://fors37na:8080/tfs");
TfsTeamProjectCollection server = new TfsTeamProjectCollection(tfsUri);
WorkItemStore workstore = server.GetService();
foreach (Project project in workstore.Projects)
{
Console.WriteLine("DefaultCollection集合下项目名称是：" + project.Name);
}
Console.WriteLine("---------------------------------------------------------------");

代码如上，在WorkItemStore workstore = server.GetService();
这一句出错，server中有信息，报错信息如下：

TF31002: Unable to connect to this Team Foundation Server: http://fors37na:8080/tfs.
Team Foundation Server Url: http://fors37na:8080/tfs.

Possible reasons for failure include:

• The name, port number, or protocol for the Team Foundation Server is incorrect.
• The Team Foundation Server is offline.
• The password has expired or is incorrect.

Technical information (for administrator):
The request failed with HTTP status 404: Not Found.

望大神解答