Haven't emulated PSP in a while so I got a fresh copy of the latest version and everything looks fine I think? I don't know much about this game.
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Googling the problem didn't yield any results either. We can try some generic advice.
1. Restore your PPSSPP settings to default. Maybe you messed with something for another game and that's causing problems here? The only thing I did to get the screenshot you see is upscaled the resolution 4x
2. Update your graphics card drivers.
3. Kinda contrary to 1 but if you don't have an nvidia card then maybe what you have doesn't like some setting and you need to mess with it? To be honest if that were the case I probably would've found someone with the same issue via Google so I don't think it's likely.
4. This may sound stupid but try rebooting your PC.
Other than that I'm stumped seeing as it worked out of the box like a charm for me.