I keep getting a message that says , The code execution cannot proceed because the UnityPlayer.dll was not found. Reinstalling the program may fix this problem.  It did not, I also got a error message saying, Missing 'app.info' in Data folder. tried reloading and reloading replacing the files but nojoy.  Help, im sure its a simple thing  Tried Jaygtaylor correction also went down to the old version .  Still nojoy 

Make sure you have downloaded the version called "FPVFreerider_2019-02-05.zip", which is marked latest version, that one should work.

I suggest deleting the entire simulator and unpacking the zip again, maybe to a different folder. Sometimes the folder name/location can make a difference.