1) Go into your TF2 directory and delete both titanfall2.exe and titanfall2_trial.exe.
2) Go into TF2 properties on Steam and validate files. Steam should re-download both files again.
3) Launch game

1) Launch Origin First in administrator mode
2) Launch Steam in administrator mode
3) Disable Origin in-game overlay in the Origin options. If for some reason that does not disable the overlay, you can also disable it by going to C:\Program Files (x86)\Origin\igo64.dll (or where ever you installed origin) and deleting or renaming the file. (make backup copy first)
4) Launch TF2 from the .exe file also in administrator mode

1) Disable any 3rd party anti virus software you may have.
2) If on Windows 10 do the following, from reddit user giub3:

Open windows defender.
open "App & browser control".
open "Exploit protection".
Below the description, written "Program settings". Click on it.
Click on "Add program to customize".
"Choose exact file path".
Find the installation path of Titanfall 2, and choose "Titanfall2.exe".
Now, click on all the "Override system settings".
Make sure that they all not allowed(that they are off), and then just click on apply.


3) Re-launch TF2

1)Re-install Origin
2)Re-install TF2
3) Try launching again.

These are just some of the solutions to this problem. If any other solutions worked for you, please let me know and I will add it to the guide.