I will try again today, to download everything again with no active anti virus program... AND with the anti virus ignoring the files you suggested.
That's what has been always suggested in every thread related to the antivirus, if the antivirus is the problem, you have to turn it off when downloading and installing, and exclude the relevant files before turning it back on and launching FSX for the first time after the installation.
I hope it will work, because as of now my sim crashes upon accepting the addon manager and couatl dlls!
Likely because the antivirus has blocked the download of the current version, so you have now a mixup between old and new files, which will cause FSX to quit ( not crash, a crash it's something with an error message) to desktop without any messages.