You are correct in that you did not say you are remote compiling. That is my bad for making that assumption. But no that’s not how this works. It outlines everything right here for you:
As it says, and as I will explain in more detail, you can only make iOS projects on Windows if they are BLUEPRINT ONLY. Since you have a custom plugin with custom C++ code, that requires actually making a full build.
Now if we had access to a Mac server to make plugin builds, we could have provided precompiled binaries for the Mac/iOS platforms (just like we did for Linux/Android) which would have allowed you to do exactly what you are trying to do. The problem is you CANNOT compile Apple software except on Apple computers, period. On the other hand Microsoft lets you compile their software on ANY platform, which is why Apple is such a ridiculous company and just further alienates anyone with actual technical expertise. It is 100% an OS for computer illiterates or technology challenged “artists” doing audio mixing or photoshopping or whatever. Therefore unless we take the time to either buy a Mac computer (never gonna happen) or rent a Mac server for the insane cost of $60/month for the most basic hardware, we have no way to compile these plugins for Apple software. It doesn’t mean that they aren’t supported, but just that we have no way to build them ourselves for you without paying for something we don’t want or need anytime soon.
So what happens is, UE4 provides precompiled binaries of the plain jane engine such as UE4Game.exe for Windows or UE4Game (with no extension) for iOS. That means when you package from the editor, the ONLY thing it is doing is COOKING and PACKAGING your game. There is zero compiling taking place on your computer for Apple sofware, at all. So what’s happening is, you’re deploying your project to your iPad, but the UE4Game application is completely missing the code for the plugin and crashing since you neither have precompiled binaries for it nor have you setup remote compiling to make them yourself.
This is why there’s a remote compiling feature built into the engine. That means instead of having to take the time to download your project to a Mac and build everything there (which is what we did when we were testing it) you can actually just setup an SSH key to remotely connect, so you can still do a full build for ALL platforms on your Windows machine, but the remote Mac will do its thing just for Mac/iOS builds.
If you want to do this, it’s pretty easy to setup, we used a service called MacStadium to do it previously, but again it’s like $60 just to rent the server to do that. There’s instructions at the end of the WebUI documentation on how to compile the plugin on Windows, and you can follow the previous link for setting up remote compiling. You would have to edit your UPLUGIN file to remove the Linux/Android platforms but leave the iOS one (and maybe even the Mac one too). Keep in mind you would have to do this for the JsonLibrary as well since it’s a required plugin for the WebUI plugin.
If you end up doing this and want to be really nice, you can run the full compile and then send us the /Binaries and /Intermediate folders for both the JsonLibrary and WebUI so we can include them in the 4.26 ZIP files for others that might want to package blueprint-only projects for Mac/iOS so they don’t have to go through the trouble you did. But that doesn’t really help in the long term because not only does that exclude everyone on previous versions of UE4 which still won’t have these precompiled binaries; the moment we make an update or bug fix we would have to throw the binaries away anyway.
Now with all that being said, we don’t really plan to update the WebUI any time soon since it already has all the features we’ve been planning the past few years. Our focus is now more on building out other plugins. So if you want to do that, we have no problem updating the 4.26 ZIP files for ALL platforms.
Otherwise your only remaining option is to contact the guy that posted the original issue on GitHub that I linked to you in my previous post. They have a full package of the WebUI for iOS already since they were the one that brought the compiler issue to our attention and confirmed that everything was fixed for iOS.