Which Prepar3D version works best with FSX add-ons (Orbx, JF, UK Mill, etc.)?

FSX add-ons in Prepar3D — what “works best” in real life

With a big FSX library, the most important thing isn’t really “which P3D version runs them best,” it’s which add-ons are actually allowed and supported in P3D.

1) The big limiter: licensing + installers
A lot of FSX-era products either:

• have a separate Prepar3D installer (or a P3D-compatible update), or
• will install into FSX only and need workarounds, or
• are simply not licensed for P3D at all.

Orbx in particular generally has had proper P3D support for many products (depending on exactly which regions/airports you own). Just Flight and UK2000/UK scenery developers are very product-specific—some have dedicated P3D versions, some don’t.

So the “best” P3D version for you is typically the one that your specific add-ons have installers/support for.

2) Practical recommendation
If your goal is to bring over a large FSX hangar/scenery library with the least friction:

• Start by making a list of your “must-have” add-ons (top 10–20).
• Check each product’s download/account page for whether you have a Prepar3D installer and which P3D major version it supports.
• Choose the P3D version that matches the majority of those installers.

Trying to pick a P3D version first and then forcing add-ons into it is usually where people end up frustrated.

3) Avoid the common trap
Even if an FSX add-on can be made to “show up” in P3D, you can still get:

• missing textures / black gauges (common with older aircraft panels),
• installer registry issues,
• scenery library layering problems,
• performance hits from older scenery methods.

That’s why I’d base the decision on supported P3D installers whenever possible.

A few quick questions so I can steer you to the cleanest route

• Which Prepar3D versions do you currently have access to (if any), and are you looking at installing it fresh on the same PC as FSX?
• Can you list a few exact titles you care about most (e.g., which Orbx regions/airports, which Just Flight aircraft, which UK “Mill” packages)?
• Are you mainly after scenery, aircraft, or both?

If you post 5–10 exact product names, I can tell you what usually ports cleanly and what tends to be trouble (and therefore which P3D version would realistically fit your library best).