Undeclared identifier errors after moving project to a "from-source" version of Unreal

I compiled the engine from source and then loaded my project using the editor and regenerated the project files for VS and tried to compile it and for some reason I’m now getting these undeclared identifier errors which were not apparent before.

The errors are similar to this (other errors also appear which are caused by this error:

Error	1	error C2065: 'FOctreeLeaf' : undeclared identifier

This doesn’t really help as an error since I can right click->“Go to declaration” on any use of FOctreeLeaf and it will open up Octree.h (which is included and is in the correct directory) and show that it exists and the header file is included so I’m not too sure what happened.

If anyone can point out the mistake it would be a great help.


#pragma once
#include "Octree.h"
#include <mutex>


struct DualGridBorderProcs{...}

class OCTREEGENERATOR_API DualGridGenerator
	std::mutex m;
	FVector orig;
	int leafCount;
	TArray<FOctreeLeaf> borderLeaves;
	TArray<FOctreeLeaf> masterLeaves;
	DualGridBorderProcs borders;
	static const INT32 CornerCellTable[8][8];
	void Generate(TArray<FOctreeLeaf> &leaves, DualGridBorderProcs border, FVector origin);
	IDualGridCell& GetCell();

class IDualGridCell{...}