Motorola Device manager won't install 'heimdall.kext' not recognised

[nmgarnett]

Hi
New guy here so hope this is the correct forum...
I'm trying to get Motorola Device Manager on my MacBook; MDM seems to install ok but I get a popup straight after install saying something about 'heimdall.kext' and install can't complete. I've Googled heimdall.kext and it's used for flashing Samsung devices. I'm at the limit of my tech knowledge and need one of you Android geniuses to advise me...
This is the complete message:

The system extension “/System/Library/Extensions/heimdall.kext” was installed improperly and cannot be used. Please try reinstalling it, or contact the product’s vendor for an update.

Hope you can help
Nick Garnett