Loads of dangerous (ce marked) kit from the Internet, have a look on big Clive. Com he tears down a lot stuff.
I'm not sure I'd want a DIY light on the outside of my apartment and if I was the landlord then I'd pursue for costs to repair the damage to the structure
They will/should default it for a call out fee, no company will disclose their engineering codes for obvious reasons.
Alternatively post your location and someone on here may be able to offer a service/default.
9 times out of 10 they are not used correctly and the cable is not crimped firmly, most other connector types reduce the cross sectional contact area hence the resistance issues.
Soldering and heat shrink is where it's at...