Hi. Have a 12/3000/120 Multiplus and need to configure following fitting new batteries. Am using VE Configure via Mk3 USB. Mk3 is detected OK but then message displayed Connect cable and switch on device. Unit is powered and connected by patch lead (straight through). So unable to access Multiplus. Old firmware so not suitable for VE Connect. 1808146.HEX. Tried two laptops now running out of ideas. Thanks.