Legacy applications connecting to Windows shares

For legacy applications that need to access file shares on your Windows server, Microsoft suggests configuring those shares with leasing mode using the -LeasingMode None parameter in PowerShell commands like New-SmbShare or Set-SmbShare. This makes the Windows server’s shares behave like SMBv1 (without modern features like oplocks and leases) while still using the more secure SMBv2 or SMBv3 protocols.

Here is an example:

# Create a new share compatible with legacy applications

New-SmbShare -Name “LegacyApp” -Path “C:\LegacyData” -LeasingMode None

# Or modify an existing share

Set-SmbShare -Name “ExistingShare” -LeasingMode None

This allows legacy applications to connect successfully without requiring the vulnerable SMBv1 protoco

https://4sysops.com/archives/windows-september-updates-break-smbv1-shares-workarounds-and-user-feedback/l.