I assume you don't know what FF13Fix actually does.

It's not something you "install" on your computer.
It's modified dynamic library file (d3d9.dll) and configuration file (FF13Fix.ini) that you just place to the game folder where the program file (ffxiiiimg.exe) is located, and it would alter how the game is being handled on DirectX 9 3D API to disable frame pacing which should result in more stable frame rates, disable periodic controller checkup to remove micro-stutters, and fix issue where game render text on screen only in 1280x720 frame despite the
rendering resolution is being higher. (e.g. 1920x1080 and more)

I don't think it would help you with game crashing.
You also didn't provide any info about hardware specifications on your PC, or which display and shadow resolution you have the settings configured for.

If you would make the effort to browse trough few pages of recent topics in discussions, you would learn that this game have common issue causing it to crash when it attempts to use more than 2GB of memory, which is limitation of how much 32-bit OS and programs could use.
This often happens when you play at higher resolution than what the game was designed for, which is 1280x720 or when you use ReShade, add HD models and textures to the game, or anything else that would make the game use more memory than what it was made for.

While 64-bit Operating System allow 64-bit programs to use more memory, FFXIII is still 32-bit program and thus limited to 2GB.

You need to patch ffxiiiimg.exe either automatically with Nova Chrysalia launcher, or manually with 4GB Patch, which is tool that allow practically any 32-bit program to use up to double the memory despite being written for 32-bit architecture.

Mind that if you would like to use both FF13Fix and 4GB Patch together, you probably need to follow instructions in FF13Fix readme file and create copy of ffxiiiimg.exe file which you then rename to untouched.exe before you apply 4GB patch.

Originally posted by Number Eight:

I assume you don't know what FF13Fix actually does.

It's not something you "install" on your computer.
It's modified dynamic library file (d3d9.dll) and configuration file (FF13Fix.ini) that you just place to the game folder where the program file (ffxiiiimg.exe) is located, and it would alter how the game is being handled on DirectX 9 3D API to disable frame pacing which should result in more stable frame rates, disable periodic controller checkup to remove micro-stutters, and fix issue where game render text on screen only in 1280x720 frame despite the
rendering resolution is being higher. (e.g. 1920x1080 and more)

I don't think it would help you with game crashing.
You also didn't provide any info about hardware specifications on your PC, or which display and shadow resolution you have the settings configured for.

If you would make the effort to browse trough few pages of recent topics in discussions, you would learn that this game have common issue causing it to crash when it attempts to use more than 2GB of memory, which is limitation of how much 32-bit OS and programs could use.
This often happens when you play at higher resolution than what the game was designed for, which is 1280x720 or when you use ReShade, add HD models and textures to the game, or anything else that would make the game use more memory than what it was made for.

While 64-bit Operating System allow 64-bit programs to use more memory, FFXIII is still 32-bit program and thus limited to 2GB.

You need to patch ffxiiiimg.exe either automatically with Nova Chrysalia launcher, or manually with 4GB Patch, which is tool that allow practically any 32-bit program to use up to double the memory despite being written for 32-bit architecture.

Mind that if you would like to use both FF13Fix and 4GB Patch together, you probably need to follow instructions in FF13Fix readme file and create copy of ffxiiiimg.exe file which you then rename to untouched.exe before you apply 4GB patch.

No matter how helpful or unhelpful what you posted is you said it like a gigantic condescending ♥♥♥♥♥♥♥ for no reason

Originally posted by wgriskell:

No matter how helpful or unhelpful what you posted is you said it like a gigantic condescending ♥♥♥♥♥♥♥ for no reason

OK... I'm "gigantic condescending ♥♥♥♥♥♥♥" for trying to explain things the way that even someone who only played video games on console till now would understand.

It was the OP's request for solution that would explicitly not include FF13Fix that made me write that wall of text in attempt to explain what FF13Fix actually does, and what could possibly help with the crashes.

Now that I also explained why I'm "gigantic condescending ♥♥♥♥♥♥♥"... I wish you to have a nice day.