after installing the SQL Server Update KB4505224 this weekend, I’m no longer able to connect to the SQL server from the network. On localhost it still works.

If I disable the windows firewall entirely it works again. Are there any known issues with this update?

My firewall rules look like this:

  • Allow everything for %ProgramFiles%\Microsoft SQL Server\MSSQL14.MYSQLSERVER\MSSQL\Binn\sqlservr.exe
  • Allow TCP and UDP for 1433 and 1434

The SQL Server uses dynamic ports.


1 Answer 1


Please download and install Cumulative Update 17 from this URL.

After installing CU17, make sure you have configured Windows Firewall as stated on this documentation.

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