Under the existing Reflection System, one of the problems seems to be that the Editor has become confused together with the Stand-alone exe and Client/Server exe builds.
Although I am now successfully compiling UE “5.6” repository. When I attempt to compile the entire Solution, as opposed to compiling just the UE5 sub-project, even more of the same types of link error show up. For example:
From stackoverflow, clamum Jan 11, 2023: “I was getting the exact error this question lists [MSB3073 UE exited with code 6] … syntax all looked fine (this project/environment worked fine the last time I used it, some months ago) and hadn’t changed, so I decided to clean the solution and rebuild. This time I got a slightly different error, and it mentioned needing Windows SDK installed. Visual Studio Installer showed under C++ Game Development that none of the Windows SDK options were checked/installed. Since I’m running Windows 10 I checked the most recent/highest version of W10SDK and installed that. I have no fricking clue what just happened here, cause this all worked last time I worked on it and I changed nothing in the meantime, but it all works now. So for others that get this, maybe: Try cleaning your solution and see if you perhaps need to install Windows SDK; Maybe upgrade your UE … a minor version, if it’s available”.
link.exe Application Error The instruction at 0x00007FFFA3E0C5D9 referenced memory at 0x0000000000000C18. The memory could not be read.
/MidiEngineTests//Plugins/MidiEngine/Intermediate/Build/Win64/x64/UnrealEditor/Development/AxMidiEnginePianos/UnrealEditor-AxMidiEnginePianos.exp
27>[26/41] Link [x64] UnrealEditor-AxMidiEnginePianos.dll (0:00.64 at +3:11)
27>LINK : fatal error LNK1181: cannot open input file ‘\UE_Games\MidiEngineTests\Plugins\MidiEngine\Intermediate\Build\Win64\x64\UnrealEditor\Development\CommonOps\UnrealEditor-CommonOps.lib’
27>Error executing \VC\Tools\MSVC\14.38.33130\bin\Hostx64\x64\link.exe (tool returned code: 1181)
And from above: “getting … linking errors that say something like: UnrealEd and MessageLog modules are not compatible with stand alone builds. And I am finding that these (and other) UE modules that are Editor specific are being included in the .Build.cs files of the third party plugin developers.”
I suspect what happened, in the zeal of the new idea of the Reflection System, so that all of the struct and class members could become revealed to the Editor. That the Editor approximately became built into the end executable (stand-alone, client and server builds).
At which point, it became the developers’ duty to know how to separate the two halves. And if not, the UE build system reports a failure to link if Editor modules are attempting to link into a stand-alone, client or server exe build.
Which then creates the problem of having to have a command level of knowledge of the whole UE source code plus all of the code of the third party Fab developers whose code you might want to try to include in your game. Which seems like an unreasonable ask for small development teams.