Unload the specified fabrication item files from the project. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 19.0.0.0 (19.0.0.405) 
  Since:  2019 
Syntax
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Parameters
- itemFiles
-  Type:  System.Collections.Generic IList   FabricationItemFile  
 The fabrication item files to unload.
Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions ArgumentException | Fabrication item files can not be unloaded if they are currently in use. -or- Some fabrication item files have not been loaded. | 
| Autodesk.Revit.Exceptions ArgumentNullException | A non-optional argument was NULL | 
| Autodesk.Revit.Exceptions InvalidOperationException | The current fabrication configuration is not connected and updated to source configuration. Reload and try again. |