Problem:
The admin-dashboard was installed once and in the meantime was removed again. After some time, a reinstallation did not work.
Solution:
The installation failed, caused by an already running admin-dashboard container, which seemed not to be deleted completely in the first time.
So check via
docker ps --all
and
docker ps
if the container exists and is already running: ps -aufx |grep grefana
than stop the container via docker stop <ContainerID>
andf try the installation again.