Can't place tiles, get error message "MATERIAL" not found in ('WIREFRAME', 'SOLID', 'RENDERED') when I click anywhere

[PanzSan]

Trying to use Sprytile with a model that already has some texture painting. New Tile sets aren't appearing in the list preview (I can see the name and tile, but not the actual image) nor the pallet. The cursor shows the tile but whenever I click I get this error message.

Python: Traceback (most recent call last):
File "C:\Users[My User Name]]\AppData\Roaming\Blender Foundation\Blender\3.0\scripts\addons\SpryTile\sprytile_modal.py", line 827, in invoke
cur_space.shading.type = 'MATERIAL'
TypeError: bpy_struct: item.attr = val: enum "MATERIAL" not found in ('WIREFRAME', 'SOLID', 'RENDERED')

location: :-1

When I use Sprytile on a new file (just the plane cube) it works fine, so it seems to be an issue with this specific file

[PanzSan]

Uploaded screenshots of the error in this Imgur Post

Palette shows up with some tampering, but error persists