LifeGeek99

Had this issue as well - uninstalling all downloaded content from the workshop didn't work, so I validated the game files (for the hundredth time), uninstalled the DLC (via Steam), and launched the game from the KSP_x64.exe file in the file system rather than through Steam. After many months trying, it finally launched correctly. Edit: Looks like it's something with how Steam launches the game. After re-installing the DLC(via Steam), it still launched (via Steam) with AUTOLOC error, but (after re-acquiring files) it launched without the error when I ran KSP_x64.exe directly.

I used Vector engines with Mk3 airplane fuel tanks and a refueling rig on the top. Works with most designs, and easy to problem to solve. Need a longer burn time? Add more fuel. Need more power? Add more Vector engines. I needed to turn the vectoring range of the engines way down, otherwise landing was almost impossible. Also, be careful with making your lander too tall. Reaction wheels can only do so much.