When a Debezium connector is being created, specifically when the Kafka Database History class is initializing storage, some default properties are retrieved from the Kafka brokers via the Kafka AdminAPI. These default properties are then used to create a database history topic for the connector.
If for whatever reason the AdminAPI does not return all the expected properties, a NPE is thrown with no description of what was missing or what went wrong. For example, if Debezium is being used with Confluent Cloud solutions, the AdminAPI in CCloud does not return the default replication factor property. More context on this issue can be found here: https://groups.google.com/forum/#!topic/debezium/4tJufQHIj38
These NPE should be handled properly, and give informative error messages.