So I've installed a fresh version of KSP 1.2.2, ran it in x64 with no mods, and copied the content's of the ZIP archive from Galileo's Planet Pack 1.2.3 (GameData > GPP/Kopernicus/MFI/MM 2.7.6) to my KSP GameData folder and then loaded up KSP x64. The game then loads to the main menu, yet Kerbin is still showing in the background, along with when I try to start a new game (brand new) it just sits at the loading screen with the rotating planets in the bottom right.
A few things I've also noticed: Whenever I've launched the game, and it get's stuck at the "Infinite Loading Screen" after the main menu, I then close the game, and I then verify the game file integrity and it always shows that 1 file failed to verify, and proceeds to re-install it. I have also removed the GPP specific folder and replaced it with just OPM and that loaded the game to the KSC just fine.
Thanks for any help/tips.
Output Log: https://www.dropbox.com/s/n7v4atxye8ghh26/output_log.txt?dl=0
Image: Directory/GameData