Collabora online not loading

Hello Folks, I’m stuck with setting up Collabora Online and need help at this point.

Running Nextcloud 15.0.5 on appache2 and latest docker container of collabora online.

Appache has a virtual host pointing to the docker on

Problem: When opening a .odt in nextcloud, collabora does not launch properly and the frame stays white with a loading icon that never finishes…

Virtual host file:

 <VirtualHost *:443>

# SSL configuration, you may want to take the easy route instead and use Lets Encrypt!
SSLEngine on
#SSLCertificateFile /path/to/signed_certificate
#SSLCertificateChainFile /path/to/intermediate_certificate
#SSLCertificateKeyFile /path/to/private/key
SSLProtocol             all -SSLv2 -SSLv3
SSLHonorCipherOrder     on

SSLCertificateFile /etc/letsencrypt/live/
SSLCertificateKeyFile /etc/letsencrypt/live/
# Encoded slashes need to be allowed
AllowEncodedSlashes NoDecode

# Container uses a unique non-signed certificate
SSLProxyEngine On
SSLProxyVerify None
SSLProxyCheckPeerCN Off
SSLProxyCheckPeerName Off

# keep the host
ProxyPreserveHost On

# static html, js, images, etc. served from loolwsd
# loleaflet is the client part of LibreOffice Online
ProxyPass           /loleaflet retry=0
ProxyPassReverse    /loleaflet

# WOPI discovery URL
ProxyPass           /hosting/discovery retry=0
ProxyPassReverse    /hosting/discovery

# Main websocket
ProxyPassMatch "/lool/(.*)/ws$" wss://$1/ws nocanon

# Admin Console websocket
ProxyPass   /lool/adminws wss://

# Download as, Fullscreen presentation and Image upload operations
ProxyPass           /lool
ProxyPassReverse    /lool

# Endpoint with information about availability of various features
ProxyPass           /hosting/capabilities retry=0
ProxyPassReverse    /hosting/capabilities

console output of browser shows following errors:


all errors are for not for the virtual host the docker container runs under.

the collabora online admin console is working properly via (virtualhost) and has working ssl certificates

Any suggestions?