Dusk WUP-028 4 GiB Junk File Bug — Workaround (#810)

Status as of 2026-05-13: Open on the Dusklight tracker.

The WUP-028 is Nintendo’s official GameCube Controller USB adapter — the one originally bundled for Smash Bros. on Wii U / Switch. It’s the most accurate way to use real GameCube controllers on PC, and Dusklight supports it. But there’s a specific interaction bug that creates a giant garbage file.

Symptom

With the WUP-028 connected, if you open Settings → Input → Controller → Configure Controller and switch the controller selection to anything other than a GameCube Controller, Dusklight writes a file of exactly 2^32 + 32 bytes (4,294,967,328 bytes ≈ 4 GiB), mostly zeros.

Effects:

• On HDD: long hang (could be minutes), Dusklight may appear frozen
• On SSD: shorter hang, but noticeable
• The junk file sits in your Dusklight data folder until you delete it

Workarounds

Option 1: Disconnect before switching

1. Quit Dusklight (or at least leave the controller settings page)
2. Physically disconnect the WUP-028 adapter from USB
3. Reopen Dusklight → Settings → Input → Controller → Configure Controller
4. Switch to your other controller normally
5. Reconnect WUP-028 afterwards if you still want it available

Option 2: Don’t switch

If you primarily use the WUP-028, keep the GCN selection active and don’t change the dropdown.

Clean up the junk file

After hitting the bug, find the oversized file in your Dusklight data folder:

• Windows: %APPDATA%\TwilitRealm\Dusk\
• macOS: ~/Library/Application Support/TwilitRealm/Dusk/
• Linux: ~/.local/share/TwilitRealm/Dusk/

Look for any file ~4 GiB that doesn’t match a known name (saves are tens of KB; shader cache is a few MB at most). Delete it. Your saves under USA/Card A/ or EUR/Card A/ are unaffected.

Related

• Windows install guide — controller setup section
• All known issues

Last updated 2026-05-14. Watch #810 for fix progress.