unexpected problem with the installation of Sophos Endpoint Security and Control

Unable to install latest version of Endpoint Security and Control on Windows 10 (1607) laptop.

I have uninstalled the previous version successfully, turned off Windows firewall, checked for any running Sophos services, tried to run as administrator and domain admin, renamed program files x86 folder to .old then eventually deleted folder, restarted, threw holy water, sacrificed a virgin goat, waved my arms, ate my lunch...still get the same error:

There was an unexpected problem with the installation of Sophos Endpoint Security and Control. Details: Sophos Management Communications System installation failed with error 0x643.

Thanks for any assistance

full log below.

10/11/2016,2:20:26 PM,Information,------------------ Beginning installation of Sophos Anti-Virus and AutoUpdate ------------------,
10/11/2016,2:20:26 PM,Information,Setup version 3.3.1.430,
10/11/2016,2:20:26 PM,Information,Command line: c:\users\username.mac\appdata\local\temp\sophos_bootstrap\setup.exe -server dzr-mcs-amzn-us-west-2-fa88.upe.p.hmr.sophos.com -token ***************** -edxtimestamp 20161011T200631Z,
10/11/2016,2:20:26 PM,Information,Process security set successfully,
10/11/2016,2:20:26 PM,Information,Setup program was run from C:\Users\username.MAC\AppData\Local\Temp\sophos_bootstrap,
10/11/2016,2:20:26 PM,Information,Checking system TMP paths.,
10/11/2016,2:20:26 PM,Information,Checking TMP...,
10/11/2016,2:20:26 PM,Information,Temp path for System found: 'C:\WINDOWS\TEMP'.,
10/11/2016,2:20:26 PM,Information,Tamper protection is not installed,
10/11/2016,2:20:26 PM,Information,Sophos Endpoint Defense is not installed,
10/11/2016,2:20:26 PM,Information,Checking if Sophos Anti-Virus or Sophos AutoUpdate are installed...,
10/11/2016,2:20:26 PM,Information,Starting wizard to collect information from user...,
10/11/2016,2:20:27 PM,Information,Checking for internet connectivity...,
10/11/2016,2:20:28 PM,Success,Successfully connected to the URL http://dci.sophosupd.com/.,
10/11/2016,2:20:28 PM,Information,Checking for internet connectivity...,
10/11/2016,2:20:28 PM,Success,Successfully connected to the URL dzr-mcs-amzn-us-west-2-fa88.upe.p.hmr.sophos.com/.../ep.,
10/11/2016,2:20:33 PM,Information,Starting the install sequence.,
10/11/2016,2:20:33 PM,Information,Checking for local third-party software...,
10/11/2016,2:20:33 PM,Information,Sending data back to Sophos...,
10/11/2016,2:20:33 PM,Success,Successfully connected to the URL d1.sophosupd.com/.../x.xml.,
10/11/2016,2:20:33 PM,Information,Done.,
10/11/2016,2:20:33 PM,Information,Installing MSI...,
10/11/2016,2:20:33 PM,Information,Copying ESCDP.dat...,
10/11/2016,2:20:33 PM,Information,SAV not present, skipping install.,
10/11/2016,2:20:33 PM,Information,Registering SAV with AutoUpdate...,
10/11/2016,2:20:33 PM,Information,Installing MCS...,
10/11/2016,2:20:33 PM,Information,Started installing C:\Users\username.MAC\AppData\Local\Temp\sophos_bootstrap\mcsep\Sophos Management Communications System.msi ...,
10/11/2016,2:20:34 PM,ERROR,There was an unexpected problem with the installation of Sophos Endpoint Security and Control. Details: Sophos Management Communications System installation failed with error 0x643,
10/11/2016,2:20:36 PM,Information,Sending EBS feedback to Sophos...,
10/11/2016,2:20:36 PM,Information,Sending data back to Sophos...,
10/11/2016,2:20:36 PM,Success,Successfully connected to the URL d1.sophosupd.com/.../x.xml.,
10/11/2016,2:20:36 PM,Information,------------------ Found errors during installation: 134 ------------------,
10/11/2016,2:20:36 PM,Information,------------------ Installation program finishing with code 134 ------------------,