[users@httpd] Missing protocol handler for scheme 'ws' for websocket proxy

[Joern Schumann <jo...@ise.fraunhofer.de>]

Hi everybody,

i read a lot of threads and discussions about similar problems, but no 
solution works for me. So i hope you can help.
I am trying to setup a websocket proxy with our apache2 server.
Therefore i enabled every needed module, you can see here:
Loaded Modules:
  core_module (static)
  so_module (static)
  watchdog_module (static)
  http_module (static)
  log_config_module (static)
  logio_module (static)
  version_module (static)
  unixd_module (static)
  access_compat_module (shared)
  alias_module (shared)
  auth_basic_module (shared)
  authn_core_module (shared)
  authn_file_module (shared)
  authz_core_module (shared)
  authz_groupfile_module (shared)
  authz_host_module (shared)
  authz_user_module (shared)
  autoindex_module (shared)
  deflate_module (shared)
  dir_module (shared)
  env_module (shared)
  filter_module (shared)
  mime_module (shared)
  mpm_prefork_module (shared)
  negotiation_module (shared)
  php7_module (shared)
  proxy_module (shared)
  proxy_ajp_module (shared)
  proxy_balancer_module (shared)
  proxy_fcgi_module (shared)
  proxy_http_module (shared)
  proxy_wstunnel_module (shared)
  reqtimeout_module (shared)
  rewrite_module (shared)
  setenvif_module (shared)
  slotmem_shm_module (shared)
  socache_shmcb_module (shared)
  ssl_module (shared)
  status_module (shared)

I tried different configurations with RewriteRules and so on, but 
nothing of them worked. All i want to have is following proxy:
ProxyPass /bdl ws://localhost:8765/

In my ErrorLogs i see this entry:
AH01144: No protocol handler was valid for the URL /bdl (scheme 'ws'). 
If you are using a DSO version of mod_proxy, make sure the proxy 
submodules are included in the configuration using LoadModule.

On client side i always get an error 500 "Internal Server Error".
Can you please help me debugging this? Believe me, i tried a lot from 
threads of the internet, but didnt find the problem.

Best regards,
Jörn