This is no longer optional for a "better" experience. Running DLC like Far Harbor (which has heavy fog effects) on an old HDD will lead to massive frame drops. Summary Checklist for a Better Setup: Download via Steam/Store (Verify PS5/Series X versions). Verify Files immediately after the download finishes. Delete the official High-Res Texture Pack if you have it. Install the Unofficial Patch to stabilize the DLC content.
Once your files are downloaded, you can make them run "better" with a few tweaks: fallout 4 dlc files download better
If your download is stuck, go to Settings > Downloads > Clear Download Cache. This often fixes "corrupt disk" errors during DLC installation. On Xbox & PlayStation This is no longer optional for a "better" experience
Right-click Fallout 4 in your library > Properties > DLC. Ensure all boxes (Far Harbor, Nuka-World, etc.) are checked. Verify Files immediately after the download finishes