I have no idea why, but SimplePlanes just up and decided not to work recently. I have verified the game files and i have moved the game across hard drives, i even uninstalled and reinstalled the game, but nothing has worked. What usually happens is the game says its running when I click "play," but then a white box appears for a second with a red exclamation mark and text that I can't read before it dissapears. Then the game shuts itself down and resets like nothing ever happened, with the "play" button back. Anyone know what my problem is?
Edit: I just found out that when I try to start the game from files it says that it can’t run because “unityplayer.dll” cannot be found. Is that something I need to download now for the game to run? Edit: I have downloaded it and put it in the file with SimplePlanes but the problem has not fixed.

Just in case anyone else has this problem, I fixed it. I forgot like an absolute fool that I moved the game across hard drives and for some reason some of my files didn’t move with the game. They weren’t deleted when I reinstalled the game, and they weren’t reinstalled and it messed everything up. Delete the files in the hard drive you don’t want it to be on and reinstall the game on the right hard drive.