Hi again Ray
It looks like ZXPInstaller doesn't yet work for DW CC 2018. I've used the DMX Zone Extension Manager and your extensions are now working nicely in DW CC 2018.
Are you aware of any issues with any of your extensions with CC 2018? I'm about to launch into a good size project which will involve all the main extensions, including eCart, so just want to check that all will be well.