Case:1

If you are unable to Launch the cluster from DataOps Application

1. Stackname should not be there in the earlier cloud formation stacks. 

2. You can go to the Cloudformation section as shown in the below image

3. Click on stack name that is started by Dataops Application you can find events tab that will show you the reason for stack failure

Case 2:

If you are unable to run the Dataflows from the existing cluster or errors in scheduled dataflows

1. you can go to the EMR clusters screen.

2. Click on the required cluster and navigate to application user interfaces you can see in below image

3. In Yarn application section we can check the required dataflow logs