[Error] filename is nil when starting the game

[Zhvair]

So I've been following the tutorial, but I'm having a problem doing a playtest. At first it went through all of the files, including pokemon, and said that physical/special attack stats cannot be at 0, and so it changed it to something else. Now whenever I try it it tries to bring up my Pokemon Uranium player (though the fanmade pokemon don't appear) and I can't even try to start a new game before the test play crashes and closes it out. Is there any way to prevent this without exporting my Pokemon Uranium to another device?
EDIT: It wasn't Uranium, it was Poketale, and I have since deleted all files of it. But it still gives me the data of the old character from it, and I still can't playtest it.
This is the error that pops up:
---------------------------
Pokemon Essentials
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[Pokémon Essentials version 17.2]

Exception: RuntimeError

Message: filename is nil

SpriteWindow_sprites:30:in `initialize'

Pokemon_Sprites:223:in `new'

Pokemon_Sprites:223:in `pokemon='

Pokemon_Sprites:209:in `initialize'

PScreen_Load:165:in `new'

PScreen_Load:165:in `pbSetParty'

PScreen_Load:164:in `each'

PScreen_Load:164:in `pbSetParty'

PScreen_Load:319:in `pbStartLoadScreen'

Main:6:in `main'



This exception was logged in

C:\Users\Zhvair\Saved Games\Pokemon Essentials\errorlog.txt.

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---------------------------
OK
---------------------------

 

[Vendily]

This is a very common error. The main issue is you have two projects with the same name and one of them has a Pokemon in the party which the other does not.
Either delete the save (not recommended) or rename the project.

 

[growl_is_broken]

This is a very common error. The main issue is you have two projects with the same name and one of them has a Pokemon in the party which the other does not.
Either delete the save (not recommended) or rename the project.

What do you mean by this? Project? Please explain step by step. I'm quite new and just had the same error right after giving myself a Fakemon and saving/quitting. By projects I assume you mean games? I only have one project right now, and I can't delete the save because I can't go into the game. How would I rename the project, and which project? Thank you!!

 

[Vendily]

What do you mean by this? Project? Please explain step by step. I'm quite new and just had the same error right after giving myself a Fakemon and saving/quitting. By projects I assume you mean games? I only have one project right now, and I can't delete the save because I can't go into the game. How would I rename the project, and which project? Thank you!!

You can rename the project by opening it in RMXP, clicking "Game>Change Title...".
Alternatively you can go to the saved games folder (my Windows 10 has it in C:\Users\Vendily-PC\Saved Games, while my Win7 had it in C:\Users\Saadia-PC\Documents\Saved Games), double click on the folder with the name of your game and delete the Game.rxdata there.

It's much easier to do the former though.

 

[growl_is_broken]

Thanks!! It worked!