How to fix Error 5543 on Windows Server 2025 / Windows 11

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Troubleshooting Guide: FILESTREAM Error 5543 – Remote Access Disabled

Why This Error Happens

This error occurs because the FILESTREAM feature on SQL Server 2025 is configured at a level that only permits local (Transact-SQL) access, while a client or application is attempting to reach FILESTREAM data remotely over the network. The mismatch typically stems from the instance-level FILESTREAM configuration not being set to “Enabled for remote clients,” or the Windows service hosting SQL Server lacks the proper file share permissions. Additionally, the Windows Firewall or SMB share settings on Windows Server 2025 may be blocking the file streaming endpoint even if SQL Server itself is configured correctly.

Step-by-Step Resolution Guide

Step 1: Enable FILESTREAM for Remote Clients in SQL Server Configuration Manager

  • Open SQL Server Configuration Manager on Windows Server 2025 / Windows 11.
  • Navigate to SQL Server Services, right-click your instance (e.g., MSSQLSERVER), and select Properties.
  • Go to the FILESTREAM tab and check all three boxes: “Enable FILESTREAM for Transact-SQL access,” “Enable FILESTREAM for file I/O access,” and “Allow remote clients to have streaming access to FILESTREAM data.”
  • Click Apply, then restart the SQL Server service.

Step 2: Update the Instance-Level FILESTREAM Access Level via T-SQL

  • Open a new query window in SQL Server Management Studio (SSMS).
  • Run the following to set access level to 3 (full remote access):
EXEC sp_configure 'filestream access level', 3;
RECONFIGURE;
  • Restart the SQL Server service for changes to take effect.

Step 3: Verify Windows File Share and Firewall Permissions

  • Confirm the FILESTREAM share name matches what’s configured in SQL Server Configuration Manager (e.g., \\ServerName\MSSQLSERVER).
  • Open Windows Defender Firewall with Advanced Security and ensure inbound rules allow SMB traffic (TCP port 445) for the subnet or client IP range.
  • Check NTFS and share-level permissions on the FILESTREAM data container path (commonly under C:\Program Files\Microsoft SQL Server\MSSQL17.MSSQLSERVER\MSSQL\DATA\) to ensure the SQL Server service account has Read/Write access.

Step 4: Restart Services and Validate Group Policy Settings

  • Restart the SQL Server (MSSQLSERVER) and SQL Server VSS Writer services from services.msc.
  • On Windows Server 2025, verify no Group Policy Object (GPO) is restricting SMB remote access or enforcing SMB signing that conflicts with FILESTREAM share protocols.

Alternative or Verification Steps

  • Run SELECT serverproperty('FilestreamEffectiveLevel'); in SSMS — a return value of 3 confirms remote access is now fully enabled.
  • If the issue persists, test connectivity using \\ServerName\ShareName from a remote machine’s File Explorer to isolate whether the problem is SQL Server configuration or a Windows networking/firewall restriction.