Wpt test returns 302 and no result generated

WebPageTest Private Instances
1

I am a software test engineer who wants to use wpt to measure our web site performance.However i met a 302 forward response when i committed a wpt test.Here is the code:
http://server_ip:8081/runtest.php
HTTP/1.1 302 Found
Location:http://server_ip:8081/result//

And /result// is certainly not found in the server and get a 404 error.

My locations.ini:

[locations]
1=ec2-ap-northeast-2
2=Test_loc
default=ec2-ap-southeast-1
;
; These are the top-level locations that are listed in the location dropdown
; Each one points to one or more browser configurations
;

[ec2-ap-northeast-2]
1=ec2-ap-northeast-2
label="Seoul, Korea - EC2 (Chrome,Firefox)"
group=Asia
;default=Test

[Test_loc]
1=Test
label="PC"
group=zch_PC

;
; Tese are the browser-specific configurations that match the configurations
; defined in the top-level locations.  Each one of these MUST match the location
; name configured on the test agent (urlblast.ini or wptdriver.ini)
;

[ec2-ap-southeast-1]
browser=Chrome,Firefox
connectivity=LAN
label="Asia location-Korea"
;relayServer="https://www.webpagetest.org/"
;relayKey=A.febf5c9cad1b8a6a5e89676652db5c95
;relayLocation=Dulles

[Test]
browser=Chrome,Firefox,IE
label="Test Location"

Any help and suggestions would be greatly appreciated!