ArcGIS Pro 2.2 API Reference Guide
CalledOnWrongThreadException Class
Members 

ArcGIS.Core Namespace : CalledOnWrongThreadException Class
Thrown when a method is called on the wrong Pro thread
Syntax
Remarks
Usually this means a method that must be called on the Pro background thread is called from the UI
Inheritance Hierarchy

System.Object
   System.Exception
      ArcGIS.Core.CalledOnWrongThreadException

Requirements

Target Platforms:Windows 10, Windows 8.1, Windows 7

See Also

Reference

CalledOnWrongThreadException Members
ArcGIS.Core Namespace