How do I install, order and manage overlays in X-Plane 12?

Install each X-Plane 12 overlay as an extracted folder inside Custom Scenery, run X-Plane once, then close it and arrange scenery_packs.ini. Put airports above object overlays, overlays above orthophoto and other base mesh, and fallback mesh last. Higher lines have higher priority; libraries must stay enabled.

Where do X-Plane 12 overlay folders go?

An overlay belongs in the Custom Scenery directory inside the X-Plane 12 installation you actually run. It adds placed scenery such as buildings, roads, forests, lighting or landmarks without supplying the underlying terrain mesh.

1. Close X-Plane: Do not add scenery or edit scenery_packs.ini while the simulator is running.
2. Extract the download: Never place the ZIP, 7z or other archive directly in Custom Scenery.
3. Find the real package folder: A typical overlay has Earth nav data directly inside its folder, often beside objects, facades, forests or library.txt. Remove any outer download wrapper that creates a path such as Custom Scenery/Product/Product/Earth nav data.
4. Install every required component: Copy each supplied package folder directly into Custom Scenery. Keep numbered prefixes and component names because they may establish the developer's intended order.
5. Register the scenery: Start X-Plane 12 once, allow it to discover the new folders, then close it.
6. Check the active configuration: Open Custom Scenery/scenery_packs.ini with a plain-text editor and confirm that each component has an enabled entry.

Some downloads contain airports, libraries and mesh alongside the overlay, so not every extracted folder belongs at the same priority. Our folder-placement checklist for downloaded X-Plane 12 scenery covers these mixed packages and the common extra-folder problem.

What is the correct scenery_packs.ini order?

Entries near the top of scenery_packs.ini have higher priority than entries below them. For a typical X-Plane 12 installation, use this order:

Package-specific instructions take precedence when a product has several interdependent folders. A mistake we see constantly is separating or alphabetically rearranging numbered components even though their prefixes were supplied to preserve an internal layering order.

Scenery libraries are dependencies rather than visible regional layers. Their exact position is usually less significant, but their SCENERY_PACK entries must remain enabled and any order specified by the package developer should be retained.

Do I need iniManager or an INI installer?

No INI manager or installer is required for an ordinary X-Plane overlay. Manual installation consists of extracting the package, placing its folders in Custom Scenery and arranging scenery_packs.ini.

If a product uses iniManager or another package-specific installer, let it install and update that product, then verify that it targets the correct X-Plane 12 installation. Some managers keep files in an external library and create links inside Custom Scenery; do not duplicate or rename those linked folders without understanding where they point.

An installer does not change X-Plane's basic priority rules unless its documentation explicitly says it manages the order. After installing or updating a package, inspect scenery_packs.ini because newly discovered folders may appear above an established mesh or overlay arrangement.

Where should an Orbx library go in X-Plane 12?

An Orbx library required by an X-Plane 12 product must be visible to the active installation as an enabled scenery package. A supplied manager may install it directly or create a link from Custom Scenery to an external library location.

The library supplies objects and textures referenced by other packages; moving it above an airport does not give those objects greater visual priority. Install the library version required by the product, keep its entry enabled, and preserve the supplied order of any separate airport, overlay, orthophoto and mesh components.

How do overlays interact with orthophotos and mesh?

An object overlay must sit above the orthophoto or base mesh whose roads, buildings and vegetation it is meant to restore. Orthophoto packages often provide terrain and imagery but need a separate overlay for three-dimensional scenery.

With Ortho4XP, the generated overlay folder commonly has a y prefix and the photo tile folders commonly have z prefixes. Keep the generated overlay above all corresponding tile folders. Our orthophoto installation and priority guide explains the remaining tile-placement details.

Only one base mesh normally wins for a given scenery tile. If another mesh has higher priority than the orthophoto, the photo imagery may disappear; reverse the order and the orthophoto replaces that mesh. Object overlays can combine, but two regional overlays covering the same area may produce doubled buildings, roads or vegetation unless one contains suitable exclusions.

Is an overlay an X-Plane 12 graphics mod?

No. An overlay changes scenery within its covered tiles; it does not alter X-Plane 12's renderer, anti-aliasing, colour processing, clouds or global lighting.

Dense overlays can still reduce performance by adding objects, vegetation, lights and draw calls. If the simulator slows only inside the overlay's coverage, test object and vegetation density settings or disable competing regional packages. If the intended change is post-processing rather than scenery, use the separate X-Plane 12 ReShade installation and configuration procedure.

How should I edit scenery_packs.ini safely?

Edit scenery_packs.ini only while X-Plane is closed, and move complete entries rather than rewriting their folder paths.

1. Back up the file: Make a copy before reorganising a large scenery collection.
2. Move complete lines: A normal active entry begins with SCENERY_PACK. Place the whole line above or below other packages.
3. Disable packages reversibly: Change SCENERY_PACK to SCENERY_PACK_DISABLED instead of deleting the folder during troubleshooting.
4. Save as plain text: Do not use a word processor that may add formatting or change the filename.
5. Restart and test the covered area: Load a location inside the overlay's actual tile coverage and compare the same viewpoint after each change.

Which scenery_packs.ini file is active?

The active file is Custom Scenery/scenery_packs.ini inside the exact X-Plane installation being launched. Separate X-Plane 11 and X-Plane 12 installations, duplicate simulator copies and backups can each contain their own file.

If an edit has no effect, confirm the executable or shortcut is launching the installation you edited. Changing an old copy elsewhere on the drive will not affect the active simulator.

Can I delete scenery_packs.ini and let X-Plane rebuild it?

Yes, X-Plane will recreate a missing scenery_packs.ini, but the rebuilt order may not correctly distinguish airports, overlays and base mesh. Deleting it can therefore undo a carefully arranged installation; backing up and repairing the existing file is safer.

Do I need OverlayEditor for X-Plane 12 or X-Plane 11?

No. OverlayEditor is a scenery-authoring utility, not an overlay installer, library manager or replacement for scenery_packs.ini. You do not need it to use downloaded overlays in X-Plane 12 or X-Plane 11, and the application itself does not belong in Custom Scenery.

Older X-Plane 11 object overlays may load in X-Plane 12 when their DSF placements and referenced assets remain compatible, but compatibility cannot be assumed for every package. Missing libraries, changed resources, forests, facades or road definitions can still cause errors.

For editing X-Plane 12 scenery, Laminar Research's WorldEditor is generally the safer choice because it supports validation for the simulator's scenery system. OverlayEditor may still be useful for simple legacy object-placement work, but make a backup before saving and never modify third-party scenery when its licence prohibits it.

Why is my custom scenery overlay not showing?

A missing overlay is usually caused by the wrong folder level, the wrong active installation, incorrect priority, incomplete geographic coverage or a missing dependency.

• Extra folder nesting: Move the folder containing Earth nav data directly into Custom Scenery.
• Wrong X-Plane copy: Check that the overlay and edited INI file belong to the installation being launched.
• Disabled or missing entry: Look for SCENERY_PACK_DISABLED or an absent package line in scenery_packs.ini.
• Overlay below mesh: Move object overlays above orthophoto and other base-mesh packages.
• Higher-priority exclusions: Airports and regional packages can contain exclusion zones that suppress objects, forests or roads from lower scenery.
• No coverage at the test location: Regional overlays only appear where their supplied DSF tiles provide coverage.
• Missing library: Open Log.txt in the main X-Plane folder and search for the package name, missing resources and DSF loading errors.
• Competing overlays: Disable other regional packages one at a time. Priority alone may not prevent duplicate objects.
• Mesh mistaken for an overlay: Base mesh cannot be stacked like object scenery; normally only the highest-priority mesh covering the tile is displayed.
• Filename case mismatch: Linux installations use case-sensitive paths, so incorrectly capitalised object or texture references can fail even when the same add-on appears to work elsewhere.

If buildings vanished after adding a terrain package, use our diagnostic steps for missing buildings above HD Mesh; the usual cause is a missing or incorrectly ordered overlay rather than the terrain itself.

How should overlays be managed after updates?

Replace an old overlay cleanly rather than leaving two versions enabled under different folder names. Preserve supplied component names, run X-Plane once to register new folders, then recheck scenery_packs.ini.

Keep a backup of a known-good INI order and disable one suspect package at a time when diagnosing conflicts. Changing several entries together makes it difficult to identify whether the fault is priority, exclusions, a missing library or the package itself.