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

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?