Hi Paul,
I thought exactly the same, and did a search for the FSUIPC.KEY but it's not on my system.
The issue seems to be because I have P3D but not FSX installed, the FSUIPC installer seems not to work properly when the search box comes up that is looking for FSX, and I cancel it. (even though it does go on to let me enter the registration - but it just does not result in the creation of a FSUIPC.KEY file :( ).
I've seen this a few times, from a Google search but have been unable to find a solution.
Ps... My install log is in the "spoiler" in the first post - a normal install, just showing no registration in the Modules folder.
I can give my licence details to Pete when he's back and perhaps he can create a FSUIPC.KEY that I can place in the Modules folder.
I only bought P3D today and absolutely everything else has gone perfectly - but I have been on for 4 hours with this FSUIPC registration problem, and have tried 3 full un/re-installs of P3D, and countless install attemptes for FSUIPC.
I have read all instructions, am using the very latest FSUIPC, a valid FSUIPC4 licence key bought from Simmarket, and a version of P3D bought an uninstalled today.
I've been using FS for 20 years and just cannot get my head around this one.