As with most things to do with the changes Dovetail Games have made, though, people are already getting around the installation issues.Copy and paste works in many cases, or redirecting the installer manually.
Things aren’t where they were and file versions, sizes and dates have changed, so that can cause problems.
On the day after release, Pete overcame serious PC problems to release FSUIPC 4.938 (available here) and many people have discovered that installing the legacy Simconnect versions found in resolved many connection issues. You can also edit, modify, copy and paste files freely within the Steam folder structure so provided you don’t break the application, you can do what you like.
Most of the sections of this article are going to end with a link to the Steam forums for more information, so here’s the first one – a list of “Addons that are working fine” But it’s on Steam. You can install the DX10 “fixes”, you can install freeware or payware at will.
On the other hand, and this is critical, most things with FSX: SE.
What stops most of them working immediately is not the code changes, but rather the executable installers for those add-ons.