Symptoms

SmartObjects were deleted and re-created, this caused the workflow to be out-of-sync. Workflow failed at several SmartObject update events:
Unable to load Sharepoint columns.

SourceCode.SmartObjects.Client.SmartObjectNotFoundException: SmartObject t57814aa4-8e43-46f3-926c-a00d1aec9687] could not be found.
at SourceCode.SmartObjects.Client.SmartObjectClientServer.GetSmartObject(Guid guid)
at SourceCode.WebDesigner.Framework.FrameworkBase.GetSmartObjectInputs(String InputData, String ExtraData)

Unable to load Sharepoint columns.

SourceCode.SmartObjects.Client.SmartObjectNotFoundException: SmartObject t57814aa4-8e43-46f3-926c-a00d1aec9687] could not be found.
at SourceCode.SmartObjects.Client.SmartObjectClientServer.GetSmartObject(Guid guid)
at SourceCode.WebDesigner.Framework.FrameworkBase.GetSmartObjectFields(String InputData, String ExtraData)
 

Diagnoses

The error message indicated that the SmartObject with the GUID GMYGUID] was missing. Perhaps, it was created with a new GUID id.
 

Resolution

Customer had a backup of the deleted SmartObject’s definition file, we removed the current SmartObjects via the SmartObject Tester tool and did an import of the current SmartObjects but used the missing SmartObjects GUID id. Customer confirmed that the issue was resolved.