Why is REX AccuSeason not working in MSFS?

REX AccuSeason usually stops working because its generated scenery package is being written to the wrong Community folder, the chosen season was not fully applied before Microsoft Flight Simulator started, or another vegetation package is overriding it. Close MSFS, verify the package path, reapply the season, remove conflicts, then restart the simulator.

How do I fix REX AccuSeason not working?

The fastest fix is to verify the active Community folder and generate a fresh seasonal package while Microsoft Flight Simulator is closed.

1. Confirm the simulator and platform. Microsoft Flight Simulator 2020 and MSFS 2024 use separate package locations. For MSFS 2024, use an AccuSeason release or mode explicitly intended for that simulator rather than directing an older installation to the 2020 folder. The desktop utility also requires Windows and cannot write packages directly to an Xbox or PlayStation console.
2. Close MSFS completely. Quit to the desktop and make sure its process has ended before AccuSeason updates any files. Open AccuSeason, select the required season or automation profile, run its apply or install command, and wait until the operation finishes without an error.
3. Check the active Community path. The decisive test is whether AccuSeason's generated package appears in the Community folder that this installation of MSFS actually reads. Store, Steam and custom installations can all use different locations; our Community-folder and package-detection checks explain how to identify the active one. MSFS 2024 users should follow the separate checks for the 2024 Packages location. If an add-on linker is involved, confirm that its link exists in that same folder and that the target drive is available.
4. Inspect the generated package. Its package folder should sit directly inside Community, with files such as manifest.json and layout.json at the package root. An extra nested folder prevents MSFS from mounting it. The AccuSeason application itself does not belong in Community; only its generated simulator package does.
5. Start MSFS in Normal Mode and remove conflicts. Safe Mode deliberately excludes Community packages. Temporarily disable every other global season, tree, biome, vegetation-density or terrain-colour modification, then test AccuSeason alone. If that works, restore the other add-ons one at a time to identify the override.
6. Check security and write permissions. If AccuSeason reports success but creates no package, Windows security, antivirus protection, insufficient free space or a read-only destination may be blocking the write. Allow the app access to the destination rather than permanently disabling security software. A successful administrator test points to a permissions problem that should be corrected at the folder level.
7. Restart rather than returning straight to the flight. MSFS mounts scenery packages during start-up and does not reliably refresh a rewritten global package while running. Our explanation of when a complete scenery reload is required covers this behaviour. If the package mounts but old colours remain, use the steps for rebuilding stale MSFS scenery caches.
8. Regenerate or repair AccuSeason. Remove only its generated output package, update or repair the desktop app through its own installer, confirm the simulator path again, and apply a fresh preset. This is preferable to copying old generated files back after a major simulator update.

How can I identify the actual AccuSeason failure?

The location of the failure tells you which fix to choose.

Why does the season still look unchanged?

AccuSeason can be working even when the difference is subtle, because not every object in Microsoft Flight Simulator uses the default vegetation assets that its package replaces.

Test at a wooded, temperate location using default scenery, fixed clear weather and the same camera position. Apply two visibly different seasonal presets, restarting MSFS after each one. Tropical and arid regions naturally show less seasonal variation, while handcrafted airports, photogrammetry and third-party scenery may supply their own trees or ground textures.

Also check which AccuSeason mode is active. A manually applied preset does not necessarily follow a date changed inside MSFS, while an automated profile depends on the utility's own scheduling. Snow is a poor test on its own because weather, surface conditions and the simulator's snow rendering also affect what appears.

Does REX AccuSeason need to stay open?

A manually generated season package normally remains available after the AccuSeason window is closed, because MSFS reads the installed package rather than the app's interface.

Automation is different: its background or scheduled component must be allowed to run when a seasonal update is due. If it rewrites the package while MSFS is already open, close and restart the simulator before judging the result.

Can the PC version work with MSFS 2024 or consoles?

MSFS 2024 on PC requires a compatible AccuSeason build and its own package path; the Windows utility cannot write to Xbox or PlayStation package storage.