Nextcloud and Collabra on Ubuntu (access denied)

Credit here to Speedysurf HERE: https://help.nextcloud.com/t/nc-11-0-3-and-collabora-access-denied/12221/2

first get the current ExecStart form your docker.service file:

    grep ExecStart /lib/systemd/system/docker.service
    the result is something like this:
    ExecStart=/usr/bin/dockerd -H fd://

now use this result to create a systemd docker drop-in configuration file. Create the service directory first therefore as well:

    mkdir /etc/systemd/system/docker.service.d
    editor /etc/systemd/system/docker.service.d/execWithDeviceMapper.conf

The file now must contain the following lines:

    [Service]
    ExecStart=
    ExecStart=/usr/bin/dockerd --storage-driver=devicemapper -H fd://

remove your old container (shamelessly stolen from @Andreas_Fuchs's post below :wink: )

    docker ps (to get the id)
    docker stop [id]
    docker rm [id]

restart systemd, docker and your container

    systemctl daemon-reload
    systemctl restart docker.service
    docker run -t -d -p 127.0.0.1:9980:9980 -e 'domain=CLOUD.DOMAIN.TLD' --restart always --cap-add MKNOD collabora/code