Error in external axis wizard

Cypherspaceman United Kingdom ✭✭
I've had a bit of a struggle with strange behaviour in the External Axis Wizard. I'm using RS 6.04.7206.1027, 64 bit, and downloaded the wizard today.
I'm compiling a mechanism with the robot mounted on an X-Y pair of linear slides, but on clicking Finish, I get the screen below, and the system does not seem to have been configured.