Does the Epic Games Launcher’s upgrade backup include the Derived Data Cache and project configuration files?

Question

When performing an upgrade via the Epic Games Launcher for Unreal Engine 5.x, the launcher creates a backup of the previous engine version in the Engine/Backup folder if the upgrade fails. The goal is to determine whether this backup also contains the Derived Data Cache and the project’s configuration files that are required for a complete rollback to the earlier engine version.
Some sources suggest that the backup preserves only engine binaries, while other project‑specific data such as the Derived Data Cache and configuration files may not be included. It remains unclear if the launcher automatically includes those project‑specific assets in the backup or if developers must manually preserve them before attempting a recovery.

Does the Engine/Backup folder also contain a copy of the Derived Data Cache after a launcher‑based upgrade?
Are the Config/DefaultEngine.ini and related .ini files preserved in the backup, or must they be saved separately?

Muntasir · Answer

Backup scope during an Epic Games Launcher upgrade
The Epic Games Launcher creates an Engine/Backup folder when a UE5 engine upgrade fails or completes, but its contents are limited to the previous engine installation. This behavior is consistent across most Launcher versions, though exact scope may vary with the specific Launcher release and the project's engine installation method.
Model-knowledge research distinguishes between what the launcher typically includes and what project-specific data it omits:

Engine binaries and editor data from the prior version are included in the backup directory.
  Derived Data Cache residing in the project's DerivedDataCache folder is not automatically included in the engine backup.
  Project configuration files such as Config/DefaultEngine.ini under the project's Config folder are not preserved in the engine backup.

Developers intending a complete rollback should manually copy the DerivedDataCache and Config directories before initiating the upgrade.
Verification: After an upgrade, open the project's Engine/Backup folder. It should contain Binaries/ and Editor/ subfolders but not DerivedDataCache/ or Config/. Compare timestamps and file counts with the project directories taken before the upgrade to confirm what was preserved.
If you are planning a rollback and need to confirm whether your specific layout preserved these assets, please confirm the engine installation method (per-project vs shared) and the exact Epic Games Launcher version in use, as these factors affect backup scope and rollback feasibility.

Does the Epic Games Launcher’s upgrade backup include the Derived Data Cache and project configuration files?

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Backup scope during an Epic Games Launcher upgrade

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