XDebug and PHPUnit - connection with xxx was not established

Hi PHPStormtrooper ;)

Introduction

I'm just switching from Netbeans 8.2 to PHPStorm. Netbeans in most cases worked just fine, fine for my purposes. But Debugging unit tests was always a mess. So I thought, use the educational advantages and give PHPStorm a try :) And woah, when Netbeans was the family car, PHPStorm is the Mercedes Benz S class. But unfortunately the maintenance function is not working... XDebug won't connect with PHPStorm...

So here are a few notes: I use PHPS on a Win10 machine, 64 bit. PHP version is 7.0.xy in combination with xdebug 2.5.xy.

When I turn on XDebug with I can connect via Telnet.

My debug config:

PHPUnit:

PHP itself:

My simple test class:

PHPStorm invokes following command:

D:\Portable\UwAmp\bin\php\php-7.013.x86vc14ts\php.exe -dxdebug.remote_enable=1 -dxdebug.remote_mode=req -dxdebug.remote_port=9000 -dxdebug.remote_host=127.0.0.1 D:\Programmierung\php_tools\php_unit\phpunit-5.6.4.phar --configuration D:\Programmierung\...\backend\phpunit.xml --filter "/::testTrue( .*)?$/" ...\Routes\TestsTest D:\Programmierung\...\backend\test\src\Routes\TestsTest.php --teamcity

I tried php.ini in different manner:, currently running:

[xdebug]
zend_extension = "php_xdebug-2.5.0rc1-7.0-vc14.dll"
;zend_extension = "php_xdebug-2.4.0rc4.dll"
;xdebug.default_enable=1
;xdebug.auto_trace = On
 xdebug.remote_enable = On
;xdebug.remote_autostart = On
xdebug.remote_connect_back = On
;xdebug.profiler_enable = On
;xdebug.profiler_enable_trigger = On
;xdebug.profiler_output_name = cachegrind.out.%t.%p
;xdebug.profiler_output_dir = "xdebug_output"
;xdebug.remote_handler=dbgp
xdebug.remote_host=127.0.0.1
xdebug.remote_port=9000

I really can't figure out what the problem is... Is there any further information I can provide?