Hi,
I’ve been struggling with this ‘error unknown error’ for quite a while now and I can’t seem to package my game. 
Any help would be super appreciated, I’m a bit of a noob when it comes to these things.
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: Visual C++ 2015 toolchain does not appear to be correctly installed. Please verify that “Common Tools for Visual C++ 2015” was selected when installing Visual Studio 2015.
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool: ERROR: Windows SDK v8.1 must be installed in order to build this target.
Could you check these 2 things
How would you like me to check them? I have visual studio but I’m unsure about windows SDK. I’m not even sure what that is 
I’ve ended up uninstalling visual studio 2015 and installing visual studio 2017, I hope that doesn’t mess things up hah.
IGorilla’s answer is correct. You’ll need to go ahead and install the C++ content for Visual Studio 2015 as well as install the Windows 8.1 SDK. A quick search on google will give you the information you need to take care of these errors. If you are still experiencing errors after resolving the two listed above, feel free to leave a comment to reopen this thread and provide your new output log.
Yeah so I reinstalled Visual studio 15 and everything seemed fine. I’m still coming up with an error that reads “PackagingResults:Error: Error Unknown Cook Failure”
I’m pretty unsure with what to do atm, It says a lot of my foliage “was not found!” I used some of the unreal starter kits for the plants.