Unhandled Exception Errors (-433980896) and (2011238796) Related to Salesforce Flows Using Entities on External Object Framework

Users encountering unhandled exception errors containing (-433980896) or (2011238796) relating to Flows using virtual entities may be experiencing errors due to indirect references to related entities.

Tooling API exposes objects like EntityDefinition and FieldDefinition that use the external object framework. That is, they don’t exist in the database but are constructed dynamically. 

For example, using EntityParticle.EntityDefinitionId to assign variables from a FieldDefinition with similar EntityDefinitionId will throw one of the above errors.