Problem Viewing forms for own pokemon

When i try to view the forms page in the pokedex for my own pokemon, shadeon. (NOTE IT DOES NOT HAVE ANY FORMS) This error comes up:

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Pokemon Essentials
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Exception: RuntimeError

Message: filename is nil

SpriteWindow:218:in `initialize'

PokemonSprite:253:in `new'

PokemonSprite:253:in `refresh'

PokemonSprite:213:in `initialize'

PokemonNestAndForm:198:in `new'

PokemonNestAndForm:198:in `pbStartScene'

PokemonNestAndForm:396:in `pbStartScreen'

PokemonPokedex:843:in `pbDexEntry'

PokemonPokedex:773:in `loop'

PokemonPokedex:846:in `pbDexEntry'

Make sure you have the graphics required for your new species.