Need help in applying changes made to the prefab (urgent)

Okay so I was recently watching this tutorial on YouTube and I am stuck on this one particular section.

At 11:07 in the video, He presses "Apply" in the inspector. Now if you look at the bottom in the Project window in Assets>Prefabs folder, the EnemyGO prefab now has an arrow next to it.

However I am unable to do this since the Apply button isn't available for me.

I tried clicking on Overrides and clicked Apply All, I don't have the arrow appear for me next to the prefab.

I am using Unity 2018.3

Please help me this is urgent.

 

maybe thats the old prefab system, unity now has new one,
https://blogs.unity3d.com/2018/06/20/introducing-new-prefab-workflows/

 

I still don't know what to do tho

 

Probably easiest to download the version of Unity used in the video https://unity3d.com/get-unity/download/archive

 

I know the issue feels very urgent to you, but try to settle down a bit and help us help you.

As @mgear said, the prefab system has changed in the newest version of Unity. You should take some time to get used to the new system and understand how it works. It's not that exceptionally different from the old system for basic uses like this.

If you're early in your game development hobby/career (which, based on this thread, I assume to be the case, but please correct me if I'm wrong), you shouldn't be in any situation where anything is urgent. It's important to understand what you're doing and why. If you're in such a rush that you're panicking to have the forum solve an issue for you like how to apply changes to a prefab, you're not focusing on learning to use the tool. And honestly, you're just going to run into another roadblock a few more steps down the road.

Slow down a bit. Don't be afraid to play with things and break everything, throw it out, and start over.

 

I'm curious how completing a beginners tutorial is something "urgent." Urgent usually means you have some time sensitive deliverable. As already mentioned, the tutorial is not updated for the new prefab system. Either learn the new prefab system elsewhere, or use a version of Unity with the old prefab system (2018.2.x or older, though using the exact version used in a tutorial is often the best solution).

 

This is a very good question OP. The answer is that instead of hitting "apply" you click the "overrides" button which will bring up a list of changes you have made to the object you are working on that differ from the original prefab. At the bottom of the list is an "apply all" button. Clicking this will apply all the changes you have made back to the original prefab. I hope this helps!

Also this video gives a good and relatively easy overview of the new workflow:

Go to 3:10 in the above video for information directly related to your question.