I created a topic under developer discussion so that meaningful work could be started on the development of a new loader.
I clearly posted that it didn't work and the errors presented.
People didn't understand and turned my thread into off topic discussion which caused the mods to merge it here.
The upgrade will install successfully because the system is still DSM 6 until it reboots, at which point it becomes DSM7 and incompatible with the loader.
DSM 7 does not work with the current loaders, do yourself a favour and stop trying to install it until a new or updated loader is released.