The "addonExecutable integrity compromised" has been discussed many times, and it's caused by other software you have installed, which is attaching to each and every running executable on your system (wasteful and potentially dangerous practice), most likely to monitor hotkeys.
A list of software that is known to cause this can be found here:
http://www.fsdreamteam.com/forum/index.php/topic,11789.msg90208.html#msg90208This caused the old Couatl 2.x version to complain, because it thought it was some kind of intrusion into it.
We removed this check in the Couatl 3.x version that is currently in Public Beta test stage, which can be obtained here:
http://www.fsdreamteam.com/forum/index.php/topic,11796.0.htmlI think it is something to do with the fact that I am running P3D 2.5 but my LSZH addon is an FSX product which I put in the addon sceneries folder of P3D (I did this with EGKK which is a UK2000 FSX product and had no problems there)
The error doesn't have anything to do with this, but this doesn't mean you can install an FSDT scenery "just" copying the \scenery folder somewhere. Only 30% of the files that are needed by the scenery are located there so, NOTHING will work if you install a scenery like that.
There IS a reason why we have an installer, and since our installers properly and correctly detect all sim version, including P3D up to the latest hotfixes, it doesn't make any sense to install manually. Remove everything you copied manually, and only use the FSDT installer.
Then, install the Couatl 3 Beta as explained above, to get rid of the "addonExecutable integrity compromised" error message.