Windows & BSOD · medium

How to fix SMB signing mismatch – network share unavailable

Error code: SMB-SIGN-MISMATCH

What this error means

Cannot connect to a Windows file share. Error: 'The network path was not found' or 'Access denied' due to SMB signing policy conflict.

Updated

Before you begin

Save open work and back up important files. Use instructions for your exact device and software version. If Windows cannot start, see the startup guide.

Work through these checks

0 of 3 complete
01Enable SMB signing on client: Set-SmbClientConfiguration -RequireSecuritySignature $true
  1. Enable SMB signing on client: Set-SmbClientConfiguration -RequireSecuritySignature $true
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
02Update NAS firmware to support SMB2/SMB3
  1. Update NAS firmware to support SMB2/SMB3
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors
03Allow TCP port 445 in Windows Firewall
  1. Allow TCP port 445 in Windows Firewall
What to expect

Check whether the original symptom still occurs.

If it does not help

Continue only if this check applies to your device. Consult its manufacturer if you are unsure.

Browse related errors

Possible causes

  • Server requires SMB signing but client has it disabled
  • Outdated NAS firmware with SMB1 only
  • Firewall blocking port 445