Rover SITL - Build Failed

Hi,

Decided to try SITL for the first time today. Running on Windows 7 I managed to get everything working OK for ArduCopter. However, when I tried my preferred platform, APMrover2, it failed. Looking at the log “undefined reference to `AP_RP” stands out (I’m not a programmer!) as a possible issue. Can anyone shed any light on a solution?

Log file attached.

Mark