Proxy_fcgi:error Windows 2012R2 Server

Hallo zusammen,

ich habe einen Windows Server2012R2 mit Seafile aufgesetzt. Bis hierhin gab es keine Probleme.
Nachdem ich aber einen Apache 2.4 Web-Server als Repuest-Proxy (nach Anleitung) einsetzten wollte, bekam ich immer im Browser einen Service Unavailable 503 Error.

Apache error.log:

[Mon May 22 11:15:36.381930 2017] [mpm_winnt:notice] [pid 2372:tid 508] AH00422: Parent: Received shutdown signal – Shutting down the server.
[Mon May 22 11:15:38.397745 2017] [mpm_winnt:notice] [pid 2708:tid 452] AH00364: Child: All worker threads have exited.
[Mon May 22 11:15:38.413385 2017] [mpm_winnt:notice] [pid 2372:tid 508] AH00430: Parent: Child process 2708 exited successfully.
[Mon May 22 11:15:39.116543 2017] [mpm_winnt:notice] [pid 3100:tid 512] AH00455: Apache/2.4.25 (Win64) configured – resuming normal operations
[Mon May 22 11:15:39.116543 2017] [mpm_winnt:notice] [pid 3100:tid 512] AH00456: Apache Lounge VC14 Server built: Dec 17 2016 11:15:57
[Mon May 22 11:15:39.116543 2017] [core:notice] [pid 3100:tid 512] AH00094: Command line: ‘c:\Apache24\bin\httpd.exe -d C:/Apache24’
[Mon May 22 11:15:39.116543 2017] [mpm_winnt:notice] [pid 3100:tid 512] AH00418: Parent: Created child process 4372
[Mon May 22 11:15:39.319669 2017] [mpm_winnt:notice] [pid 4372:tid 460] AH00354: Child: Starting 64 worker threads.
[Mon May 22 11:15:46.746856 2017] [proxy:error] [pid 4372:tid 980] (OS 10061)No connection could be made because the target machine actively refused it. : AH00957: FCGI: attempt to connect to 172.16.1.127:8000 (172.16.1.127) failed
[Mon May 22 11:15:46.746856 2017] [proxy_fcgi:error] [pid 4372:tid 980] [client ::1:54179] AH01079: failed to make connection to backend: 172.16.1.127
[Mon May 22 11:15:47.789800 2017] [proxy:error] [pid 4372:tid 976] (OS 10061)No connection could be made because the target machine actively refused it. : AH00957: FCGI: attempt to connect to 172.16.1.127:8000 (172.16.1.127) failed
[Mon May 22 11:15:47.789800 2017] [proxy_fcgi:error] [pid 4372:tid 976] [client ::1:54182] AH01079: failed to make connection to backend: 172.16.1.127

Vielen Dank im Voraus.