First off, i searched for a solution to my problem but it turns out that there hasn't been a real solution nor anyone who has had the same (detailed) problem as i do.

When i create a new server and actually get in to the game, the whole game freezes in about 3 - 5 seconds upon entering. It gives me no other option but to close the game through Task Manager. I do take note that i was running a Tibia Server (yeah yeah, relax lol) Does this problem have something to do with the LUA or something else? I did not have any Errors in the console when i checked it before i crashed.

Well try a new game without any lua scripts and see if it works.

I've realized that it does work without Lua scripts, and that it also works sometimes when i go in game (but i just have to wait for CS2D to respond). Also i've noticed that the increase of monsters on the map causes the game to lag... why?

The initialization of Tibia RPG might not be smooth because it creates many images. This is generally not an issue for dedicated servers because they don't render them, where as listen servers do.

Your options are:

Be patient. If you wait for CS2D to respond (as you said), you can play. You might want to limit the number of monsters that spawn too.

Run it on a dedicated server. You don't necessarily have to rent another server, just run the dedicated application, then join the server hosted on your own computer. (Download assuming Windows)

It seems that the 2nd option where as running it on a dedicated server doesn't work either, because the server just doesn't respond and i get timed out when i try to join it from the server list.

Try to give the server files to a friend. Ask him to run it and play in it for a few secondes , if that works then the problem is from your pc otherwise you used a big map or you typed to much codes ( to much lines ).

Are you actually playing the script for 3-5 seconds or does it freeze on load?

I have dealt with the script numerous times and can tell you that the Tibia script just takes long to load. Eventually it will start, and playing on New Game is really not a big deal with the amount of monsters you have set the limit to.

I had the same problem is just because your computer is slow,So it can't survive()

I will explain :
My computer too when i downloaded in first time kalis rpg and i went to New game it wonted work.
So that's mean you need to remove some thinks.
If in your new game you puted Tibia lua :
First go to cs2d folder sys/lua/cs2dtibia/saves
And delet all
And try if it's start again the same problem
So just go to sys/lua/Cs2dtibia/items
And remove some items
And remove some NPC's