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TAC Xenta servers are going offline in TAC Vista

TAC Xenta servers are going offline in TAC Vista


Windows update KB4519976 causes all Xenta servers to go offline in TAC Vista every few minutes.

Product Line

TAC Vista


  • TAC Vista Server
  • Microsoft Windows 7 or Microsoft Windows 2008 Server
  • Xenta 500
  • Xenta 700
  • Xenta 900


After the Windows update, KB4519976 is installed, the SSL handshake behavior is changed. This affects TAC Vista and its communication with the TAC Xenta server.


There are two workarounds available at the moment.

Solution 1:

Uninstall  Windows update KB4519976

Solution 2:

Turn off SSL for the communication between TAC Vista and the  TAC Xenta server using the registry setting shown below. This means that only the login will be encrypted when TAC Vista is communicating with the TAC Xenta servers.

  1. Run the utility TacosTweak.exe, located in the program folder where TAC Vista is installed.

  2. Set "Only use SSL for login to TAC Xenta Servers(5xx/7xx)" to 1 to run the communication between TAC Vista and TAC Xenta servers without SSL.
  3. Restart the TAC Vista server for the changes to take effect.
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