Exercise-5: Croc.odb doesn't load

[Eulerianial]

While trying to do the exercise-5 as per https://vlsi.ethz.ch/wiki/Exercise_-_Introduction_to_OpenRoad, loading of the Croc.odb doesn't work.
Instead of seeing the routed database, the OpenRoad shows a black view.

Steps I did are as follows:

1. Installed the docker image from the iic-osci github.
2. Launched the docker image (I used the vnc server)
3. Inside the docker image check out then OpenRoad branch of the repo:

git clone https://github.com/pulp-platform/croc.git
cd croc
git checkout ex05

4. Launched openroad inside the docker image from the croc/openroad directory
5. Open DB from the menu for the 'croc.odb' inside the 'out' directory.

OpenRoad doesn't show the routed database.