Error 1603 because of existing SQL installation
Please extend the help and change installation routine for sqlcmd.exe usage;
Currently it does use it from PATH. But if you have a newer MS SQL installed (e.g. by a different application), it is not compatible. A generic error 1603 to setup DB will be thrown during installation.
The solution is to kinda hardcode the path to sqlcmd.exe fitting to Sophos SQL needs!
Cost me hours and I had to debug your setup routine!