Codeception - Can't connect to Webdriver (Acceptance Test) - selenium

Question

I can access url and create sessions:
http://localhost:4444/wd/hub/static/resource/hub.html
but when i execute ./codecept run i get an error, but i have Selenium Server running:
[ConnectionException] Can't connect to Webdriver at http://127.0.0.1:4444/wd/hub. Please make sure that Selenium Server or PhantomJS is running.
To execute Selenium Server, i used this command:
java -Dwebdriver.gecko.driver=./geckodriver -jar "selenium-server-standalone-3.12.0.jar"
I tried too with IE and Chrome (i have the same problem too):
java -Dwebdriver.chrome.driver=./chromedriver -jar "selenium-server-standalone-3.12.0.jar"
java -Dwebdriver.ie.driver=./IEDriverServer -jar "selenium-server-standalone-3.12.0.jar"
acceptance.suite.yml
class_name: AcceptanceTester
modules:
enabled:
- WebDriver
- \Helper\Acceptance
config:
WebDriver:
url: 'http://localhost'
browser: firefox
window_size: 820x1000
Codeception Version: 2.4.1
WebDriver Chrome Version: 2.38 (win32)
WebDriver Firefox Version: 0.20.1 (x64)
Chrome Version: 66.0.3359.139 (64-bit)
Firefox Version: Firefox Quantum 60.0 (64-bit)
Windows Version: Windows 8.1 64bit
Selenium Version: 3.12.0

Answer 1

To start Selenium Server you need not require to pass/specify the WebDriver variant and you can start the Selenium Server as follows :
Command :
>java -jar selenium-server-standalone-3.12.0.jar
Console Logs :
C:\Utility\selenium-server-standalone>java -jar selenium-server-standalone-3.12.0.jar
15:28:28.249 INFO [GridLauncherV3.launch] - Selenium build info: version: '3.12.0', revision: '7c6e0b3'
15:28:28.251 INFO [GridLauncherV3$1.launch] - Launching a standalone Selenium Server on port 4444
2018-05-11 15:28:28.361:INFO::main: Logging initialized #467ms to org.seleniumhq.jetty9.util.log.StdErrLog
15:28:28.860 INFO [SeleniumServer.boot] - Selenium Server is up and running on port 4444
Snapshot of the Resource Hub :
Update
As per the documentation at codeception.com the acceptance.suite.yml should have been as follows :
modules:
enabled:
- WebDriver:
url: 'http://localhost/'
browser: firefox
window_size: 820x1000

Answer 2

Problem fixed. I was using proxy.
For future users with same problem like me, can follow the steps.
First, check if you have proxy defined with this command:
echo %http_proxy%
If return some result, you need set a empty proxy with this command:
set http_proxy=
You need define a proxy always you are opening a new command line.