This is a super quick exploration into the Just Cause 3 "Task" save file. This is the state of things discovered on your map (such as Settlements, Wingsuit Challenges, etc.).

JustCause3TaskSaveEdit.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Tasks
{
	class Program
	{
		// 48 byte header
		class Header
		{
			public uint UnknownA; // 4
			public uint ZeroA;
			public uint OneA;
			public uint ZeroB;
			public uint ZeroC;
			public uint UnknownB; // 24
			public uint OneB;
			public uint ZeroD;
			public uint ZeroE;
			public uint UnknownC;
			public uint DynamicFileSize; // Doesn't include 48 byte header
			public uint Padding;
		}

		class HeaderTwo
		{
			public uint UnknownA;
			public uint UnknownB;
			public uint UnknownC;
			public uint UnknownD;
			public uint UnknownE;
			public uint UnknownF; // 24
			public uint UnknownG;
			public uint UnknownH;
			public uint EntryCount; // 36
			public uint Padding;
		}

		class ScoreEntry
		{
			public uint Type;
			public uint Type2;
			public ulong Score;
			public ulong Score2;
		}

		static void Main(string[] args)
		{
			using (var fileStream = new BinaryReader(File.Open(@"C:\Users\Matt\Documents\Square Enix\Just Cause 3\Saves\76561197990416387\tasks", FileMode.Open, FileAccess.Read)))
			{
				Header header = new Header();
				header.UnknownA = fileStream.ReadUInt32();
				header.ZeroA = fileStream.ReadUInt32();
				header.OneA = fileStream.ReadUInt32();
				header.ZeroB = fileStream.ReadUInt32();
				header.ZeroC = fileStream.ReadUInt32();
				header.UnknownB = fileStream.ReadUInt32();
				header.OneB = fileStream.ReadUInt32();
				header.ZeroD = fileStream.ReadUInt32();
				header.ZeroE = fileStream.ReadUInt32();
				header.UnknownC = fileStream.ReadUInt32();
				header.DynamicFileSize = fileStream.ReadUInt32();
				header.Padding = fileStream.ReadUInt32();

				HeaderTwo header2 = new HeaderTwo();
				header2.UnknownA = fileStream.ReadUInt32();
				header2.UnknownB = fileStream.ReadUInt32();
				header2.UnknownC = fileStream.ReadUInt32();
				header2.UnknownD = fileStream.ReadUInt32();
				header2.UnknownE = fileStream.ReadUInt32();
				header2.UnknownF = fileStream.ReadUInt32();
				header2.UnknownG = fileStream.ReadUInt32();
				header2.UnknownH = fileStream.ReadUInt32();
				header2.EntryCount = fileStream.ReadUInt32();
				header2.Padding = fileStream.ReadUInt32();

				Console.WriteLine($"Size: {header.DynamicFileSize + 48}, Task Count: {header2.EntryCount}");
				List<ScoreEntry> tasks = new List<ScoreEntry>();
				for(int i = 0; i < header2.EntryCount; i++)
				{
					ScoreEntry entry = new ScoreEntry();
					entry.Type = fileStream.ReadUInt32();
					entry.Type2 = fileStream.ReadUInt32();
					entry.Score = fileStream.ReadUInt64();
					entry.Score2 = fileStream.ReadUInt64();

					long bytesLeft = (header.DynamicFileSize + 48) - fileStream.BaseStream.Position;
					Console.WriteLine($"[{i}] Type: {entry.Type} Type2: {entry.Type2} Score: {entry.Score} Score2: {entry.Score2} TypeMatch: {entry.Type == entry.Type2} ScoreMatch: {entry.Score == entry.Score2} bytesLeft: {bytesLeft}");

					tasks.Add(entry);
				}
			}
		}
	}
}