Unresolved external symbol when upgraded to 4.6.0

Development Programming & Scripting
1

Hi. I just upgraded my project to new version, 4.6.0 release. Just before the upgrade everything worked just fine. I have 40 of these errors:

1>PartManager.cpp.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __cdecl FJsonValueString::FJsonValueString(class FString const &)" (__imp_??0FJsonValueString@@QEAA@AEBVFString@@@Z) referenced in function "private: static bool __cdecl FJsonSerializer::Deserialize<wchar_t>(class TSharedRef<class TJsonReader<wchar_t>,0> const &,struct FJsonSerializer::StackState &)" (??$Deserialize@_W@FJsonSerializer@@CA_NAEBV?$TSharedRef@V?$TJsonReader@_W@@$0A@@@AEAUStackState@0@@Z)

My .cpp:

#include "Krafts.h"
#include "PartManager.h"

#include "Runtime/JsonUtilities/Public/JsonUtilities.h" // <==== this is really necessary here if converting Json
#include "Runtime/JsonUtilities/Public/JsonObjectConverter.h" // <==== this is really necessary here if converting Json

#include "CoreMisc.h"

UPartManager::UPartManager(const class FObjectInitializer& PCIP)
	: Super(PCIP)
{
	bIsInitiated = false;
}

void UPartManager::Initiate()
{
	dprint("initiating PartManager");

	FString JsonRaw = " {  blah blah JSon  }";
	
	//parse json
	TSharedRef<TJsonReader<TCHAR>> JsonReader = TJsonReaderFactory<TCHAR>::Create(JsonRaw);
	if (FJsonSerializer::Deserialize(JsonReader, JsonPartReference))
	{
		dprint("Part Reference Json Loaded");

		bIsInitiated = true;
	}
}

The code is really skethcy, I’ve just started on this project while still trying to learn inner workings of the engine. Still, I can’t decypher the error message and feel really confused.

So while I poke around by myself, trying to fix this, maybe someone here with more experience could respond sooner, and help me out?

2

Aaaand I got it.

I didn’t have “Json” module included in my project .Build.cs

I had just

PublicDependencyModuleNames.AddRange(new string[] { "JsonUtilities" });

When I should have had

PublicDependencyModuleNames.AddRange(new string[] { "Json", "JsonUtilities" });

Strangely, it worked just fine in 4.5.1, I wasn’t even aware of the existence of this module. I thought JsonUtilities does all the magick.

Anyways, hope this post helps someone in the future.

1 Like
3

Yep it sure did, got bit by the exact same issue. Thanks!

4

You have to add “RHI” to PublicDependencyModuleNames, in the Myprojectname.Build.cs file.

5

Guys is this still working for you in 4.10? After adding Json and JsonUtilities and including JsonObjectConverter.h I have lot of compiler errors at JsonUtilitiesConverter.h file.

6

Hi Raool,

This post is from December 2014. The editor has gone through a significant amount of changes during this time. It would be best if you open a new post detailing the specific error you are experiencing and what steps you are taking to get to that point.