Stuck on "Generating World" screen (one particular world)

So I'm currently making a parkour map. The last thing I did was break a floating command block that had no command in it. I then exited the world by pressing the Save and Quit button. From that point on, I haven't been able to join the world. It's just stuck on the Generating World screen. It's not frozen because the game facts/tips still change. 

I know this was a big issue during 1.12, but when people experienced this problem in 1.12, this problem would always occur after they entered/exited the Nether or End. I have not entered or exited the End or Nether yet in the world.

Attached to this is the game file if anyone needs to see it. I tried copying the file and importing that into Minecraft, and it still didn't work. I really want this problem fixed because I spent a lot of time on this world that I won't get back.

The world isn't using any resource/behavior packs. There's no mods or addons. Other worlds work just fine, just this one is the weird one. 

 

Here is a video showing what I'm talking about: https://youtu.be/kMZaOMyVqo4

 

(The video was more than 10 mb, so I had to upload it to YouTube.)