[Graphics] i have messed up very badly and hex maniac advance won't let me import over it

[PikaJade]

I was trying to edit the battle text box in FireRed using Hex Maniac Advance, but something went horribly wrong at some point (somehow), and now it looks like this:

https://imgur.com/a/VXgrGC1

Worth noting that the top right pieces of a text box aren't even part of the tileset.
I tried grabbing a clean ROM of FireRed to get the original text box tileset, but when I tried, the "Import" button on the broken text box tileset was grayed out.
What might be causing this? How can I fix it? Is there anything else I could potentially do to get myself out of this situation?

 

[PikaJade]

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