Duplicate InternalName of the Site column

A duplicate name "<string>" was found. at Microsoft.SharePoint.SPFieldCollection.AddFieldToWeb(String strXml, Boolean checkDisplayName) at Microsoft.SharePoint.SPFieldCollection.AddFieldAsXmlInternal(String schemaXml, Boolean addToDefaultView, SPAddFieldOptions op) at Microsoft.SharePoint.Deployment.FieldTemplateSerializer.CreateField(SPWeb web, SerializationInfoHelper infoHelper) at Microsoft.SharePoint.Deployment.FieldTemplateSerializer.SetObjectData(Object obj, SerializationInfo info, StreamingContext context, ISurrogateSelector selector) at Microsoft.SharePoint.Deployment.XmlFormatter.ParseObject(Type objectType, Boolean isChildObject) at Microsoft.SharePoint.Deployment.XmlFormatter.DeserializeObject(Type objectType, Boolean isChildObject, DeploymentObject envelope) at Microsoft.SharePoint.Deployment.XmlFormatter.Deserialize(Stream serializationStream) at Microsoft.SharePoint.Deployment.ObjectSerializer.Deserialize(Stream serializationStream) at Microsoft.SharePoint.Deployment.ImportObjectManager.ProcessObject(XmlReader xmlReader) at Microsoft.SharePoint.Deployment.SPImport.DeserializeObjects()…

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