EXEC: first deploy jboss-eap64-openshift builder image
ASSERT: wait until deployment is finished
EXEC: delete the deployment
EXEC: deploy the image that has been produced (172.30.159.75:5000/ddd/jboss-eap64-openshift:latest if my project was ddd)
ASSERT: error dialog is shown NPE is generated because image has one or several env variables with no value (XXXX=)

As this first scenario seems to be valid only if you're working with CDK2.2 and no proxy set, here is a scenario valid for all versions of CDK:
ASSERT: have a Docker file with an empty ENV value. You can use https://github.com/redhat-helloworld-msa/aloha and edit the Docker file and add the following statement:

ENV NOVALUE ""

EXEC: build the Docker image on the CDK Docker connection. If you use aloha (https://github.com/redhat-helloworld-msa/aloha), then you must beforehand run the "mvn package" command to get binary artifacts being produced. Select the Dockerfile, click Run As -> Docker Image Build, select the CDK Docker connection and give msa/aloha:1 as image name
ASSERT: your Docker image has been generated
EXEC: from the Openshift explorer, select the Deploy Docker Image, then select the CDK Docker Connection, then click on Browse and select the msa/aloha:1 image, then click on the Next button
ASSERT: you should get an error