Syntax error in RawMesh.h?

C2144 syntax error: ‘void’ should be preceded by ‘;’ \RawMesh\Public\RawMesh.h → Line 58
C4430 missing type specifier - int assumed. Note: C++ does not support default-int \RawMesh\Public\RawMesh.h → Line58

Surprisingly, the first time reporting error in the internal UE4 library files. Every RAWMESH_API functions have red underlines

RAWMESH_API functions with red underline:

	/** Empties all data streams. */
	RAWMESH_API void Empty();

	/** 
	 * Returns true if the mesh contains valid information.
	 *  - Validates that stream sizes match.
	 *  - Validates that there is at least one texture coordinate.
	 *  - Validates that indices are valid positions in the vertex stream.
	 */
	RAWMESH_API bool IsValid() const;

	/** 
	 * Returns true if the mesh contains valid information or slightly invalid information that we can fix.
	 *  - Validates that stream sizes match.
	 *  - Validates that there is at least one texture coordinate.
	 *  - Validates that indices are valid positions in the vertex stream.
	 */
	RAWMESH_API bool IsValidOrFixable() const;

	/** Helper for getting the position of a wedge. */
	FORCEINLINE FVector GetWedgePosition(int32 WedgeIndex) const
	{
		return VertexPositions[WedgeIndices[WedgeIndex]];
	}

	/**
	 * Compacts materials by removing any that have no associated triangles.
	 * Also updates the material index map.
	 */
	RAWMESH_API void CompactMaterialIndices();

};

/**
* Add the raw mesh data to an archive
*
*/
RAWMESH_API FArchive& operator<<(FArchive& Ar, FRawMesh& RawMesh);


/**
 * Bulk data storage for raw meshes.
 */
class FRawMeshBulkData
{
	/** Internally store bulk data as bytes. */
	FByteBulkData BulkData;
	/** GUID associated with the data stored herein. */
	FGuid Guid;
	/** If true, the GUID is actually a hash of the contents. */
	bool bGuidIsHash;

public:
	/** Default constructor. */
	RAWMESH_API FRawMeshBulkData();

#if WITH_EDITORONLY_DATA
	/** Serialization. */
	RAWMESH_API void Serialize(class FArchive& Ar, class UObject* Owner);

	/** Store a new raw mesh in the bulk data. */
	RAWMESH_API void SaveRawMesh(struct FRawMesh& InMesh);

	/** Load the raw mesh from bulk data. */
	RAWMESH_API void LoadRawMesh(struct FRawMesh& OutMesh);

	/** Retrieve a string uniquely identifying the contents of this bulk data. */
	RAWMESH_API FString GetIdString() const;

	/** Uses a hash as the GUID, useful to prevent creating new GUIDs on load for legacy assets. */
	RAWMESH_API void UseHashAsGuid(class UObject* Owner);

	RAWMESH_API const FByteBulkData& GetBulkData() const;

	/** Returns true if no bulk data is available for this mesh. */
	FORCEINLINE bool IsEmpty() const { return BulkData.GetBulkDataSize() == 0; }

	/** Returns true if no bulk data is available for this mesh. */
	RAWMESH_API void Empty();
#endif // #if WITH_EDITORONLY_DATA
};

You need to place "RawMesh" in PrivateDependencyModuleNames (and /or PublicDependencyModuleNames) in <ProjectName>.Build.cs