---
title: "MSSQLSERVER_12301 | Microsoft Docs"
ms.custom: ""
ms.date: "03/06/2017"
ms.prod: "sql-server-2014"
ms.reviewer: ""
ms.technology: supportability
ms.topic: conceptual
helpviewer_keywords: 
  - "12301 (Database Engine error)"
ms.assetid: 69455df4-4ce9-4a6f-af5a-8bbc93e21245
author: MashaMSFT
ms.author: mathoma
manager: craigg
---
# MSSQLSERVER_12301
    
## Details  
  
|||  
|-|-|  
|Product Name|SQL Server|  
|Event ID|12301|  
|Event Source|MSSQLSERVER|  
|Component|SQLEngine|  
|Symbolic Name|HK_UNSUPPORTED_NULLABLE_COLUMNS|  
|Message Text|Nullable columns in the index key are not supported with '*construct*'.|  
  
## User Action  
 Do not use nullable columns in the index key.  
  
## See Also  
 [In-Memory OLTP (In-Memory Optimization)](../in-memory-oltp/in-memory-oltp-in-memory-optimization.md)