Think I boned it.

[peridoot]

ksp.log isnt supposed to be 414 MB long right?

[DeadJohn]

That's big but not unheard of. How long have you had your game session open?

The size of the log files reset every time you restart the game. If you've been playing for a very long time, have lots of mods, have mods that conflict with each other, and/or have a bugged mod the log files can become enormous.

If you play career mode and use the strategy building, be warned that strategies which translate one form of "income" (funds/science/reputation) into another form can spam the log file. It's a KSP bug.

Save your progress, quit, restart, then keep on eye on how rapidly the log file grows. If it happens again, find an editor that can open your large file and look for repetitive spammed messages.