If you accidentally create a circular reference inside of a datatype by creating an instance of the same datatype as a child of itself, it results in the crash of the designer with a stack overflow error.
ExecutionException: com.inductiveautomation.ignition.client.gateway_interface.GatewayException: java.lang.StackOverflowError
caused by GatewayException: java.lang.StackOverflowError
caused by ExecutionException: java.lang.StackOverflowError
Ignition v8.0.0-beta0 (b2019010302)
Java: Azul Systems, Inc. 11.0.1