UE4 Failed to produce item .dll

Failed to produce item:
G:\UnrealEngine\M2\Binaries\Win64\UE4Editor-M2.dll M2 G:\UnrealEngine\M2\Intermediate\ProjectFiles\ERROR 1

I could always create C++ projects, but now there is a problem. My friend also has this situation.

The reason is not in the “???” path of the bug report. The same error I get with the normal path.

My first guess would be that the project configuration is broken. Does this error still persist if you delete the Intermediate, DerivedDataCache and Saved folders and re-generate your project files?
Can you tell us what should be in the paths instead of ??? (probably M2 or ykyu)? Do you have a clue what change on your project (or the engine or your system) might have introduced this error?

It happens with any project on any version of engine.

I moved the engine to another ssd, can this be the reason?

I don’t think that the drive should matter too much, but for now I really would recommend a conservative handling of your paths and trying to avoid any non-ANSI and whitespace characters in them. Then it would be good if you could provide a build log as it possibly could contain further hints on what is going wrong.

Ok, I guess the problem is in the ???.. I’ll try to fix it
Thank you for your answer!

Your first problem is that you might be using extended UTF-8 characters that are not ASCII; UE4 does not currently support UTF-8 in path-naming systems. That is, rename your folders and files that are part of the project’s path such that there will be no UTF-8 extended characters(just use ASCII). Your second problem is that in order to build your project, your currently installed MVS C++ compiler toolchain requires you to have a version of the SDK in order to build the project on your machine. So you might want to google that.