That file called "UnityFramework.framework" in the Build folder is the *compiled* (i.e. *binary*) version of the Unity framework, which contains the game engine and all your game logic. Almost everything you create in the Unity editor ends up in this file, and the process that creates it is called _compilation_. At the end of the build process, you can see that file like a big DLL that your game app will load upon startup when it is launched on iOS. And that chaotic matrix you see if you force-open it in Visual Studio is just the hexadecimal representation of its binary data.
You seem to be unfamiliar with the basic concepts of compilation. I will provide a simplified explanation but I consider each user of any build system (whichever one it is) should know these basics.
At the beginning of the process you have source code, i.e. text files containing quasi-english keywords with lots of parentheses, square brackets and mathematical expressions. That is your program. This source code describes the program logic. You feed these files to a compiler which will produce *object* code, that is to say, the binary representation of that logic in specific machine instructions for the very machine type on which you intend to run the program. In your situation the compiler takes your source code files, and produces binary files (one for each source file) containing bytes that the CPUs that are inside iOS devices can understand and execute as valid binary instructions. The next step is to merge all those files together. That is called "linking" them. We call for this a program called a "linker" that will take all those object files, concatenate them and adjust the relative offsets it can find in each of them so that they all point at each other correctly, then add a program loader prefix in a platform-specific format (on Windows it's "PE", on macOS/iOS it's "Mach-O"). At this point, the linker has produced either an executable program (ending in .exe on Windows, or with no particular extension on other platforms, such as your main iOS game executable), or a dynamically loadable library or framework that's roughly a DLL with embedded resources (as is the case here with that Unity framework).
No programmer in its right mind would "edit" a file past the compilation stage to fix things, so don't even try to touch that UnityFramework.framework file in a hex editor. Except for highly skilled people, these files are untranslatable. The sane way to fix stuff is to edit the source code so as to change the game logic, and rebuild it all so that the new game logic is compiled and linked in a new executable that behaves in the appropriate way.
And since with Unity the source code itself is automatically generated by the Unity editor (that's the core of their business: they promise non-programmers they can create games because the Unity editor will literally *write the platform-specific code on their behalf*), you have to fix it one step above, i.e. in the Unity editor itself.
If you scoured all places in the Unity editor and found nothing to fix, maybe it's a known problem with that version of the editor, and you could consider upgrading to a newer version of Unity.
Good luck, I honestly don't know how I could help you beyond that point.
