Hi Ryan,
Thank you for attaching the Log.txt file. I don't fully understand some of the jargon used but learning.
What I have interpreted is:-
1. The installation of X-Plane appears to be correct to me including the 3rd party add-on; and
2. You have purchased a 3rd party aircraft from Airfoillabs, namely the Cessna 172SP and it is this add-on causing your problem as shown in the last few lines of the log.txt file.
My suggestion is to temporarily remove the add-on aircraft and relocate it elsewhere outside the X-Plane directory. Then start X-Plane..
If XP does start without any problems then, in my opinion the problem is with the 3rd party software. Your probable comment is "We know that".
What version of the Cessna are you using from Airfoillabs. Have a look at the following link found at https://www.youtube.com/watch?v=CrwiZzc18II When you make the link and after the terrible video presentation scroll down the page to view the comments. At the comment by Marcus Anderson click on the response tab from Airfoillabs. Apparently there is a glitch/problem with the software.
Then after clicking on the website "support tab" found at https://www.airfoillabs.com/bug-reports scroll well down the page to the heading called "My activation key does not work" Appears they recognise there is a problem like you are having.
My suggestion now is to make direct contact with Airfoillabs to seek their advice and solution to your problem.
Please advise on the outcome.
Good luck
Glenn