If you do not see d9k1.9k anywhere in the text, it might be a hidden character or a copy-paste error from a website.
If the wofu set continues to fail, try playing a different version, such as wof (World) or wofj (Japan), which might not require this specific, rare PAL file dump. Summary of d9k1.9k Status in MAME d9k1.9k not found