Same problem - USB not found. Tried two different USB sticks just in case. Rang Samsung support, after long conversation and lots of checks support eng. concluded possible fault on TV, eng to call.
So at this point I have a working TV that goes through "Kit detected ....." then fails to find software on USB every time TV is turned on.
Eng arrives two days later - fits new main board inTV. Now nothing happens when kit plugged in ! Eng. states kit faulty, send it back. I pointed out it was detected with the previous board an hour ago, so out comes the old card from its box, checks kit fits in socket ok, disconnects TV from all its cables and places face down working stand, paces kit into socket and preses down hard - ahhh it goes further in. TV back in place, cables connected, and ....nothing works! TV sits with a relay clicking every few secs (power overload ?) Eng. vanishes behind TV and after a few muttered words gets TV to turn on followed by " I'll be back Friday to take it to the workshop". After he left the TV started to turn off at random.
At this point I have a sick TV, a dead evolution kit, and I am looking forward to at least a weekend without any TV at all - is the kit worth it ????