The easiest way for someone to help you is to look at your log files. Anything else is just guessing and a waste of time. They will need the entire file. Not a screenshot. Not a copy/paste of an exception you found. The whole thing.
The main log file is named KSP.log and sits in the same directory as the KSP executable. For default installs on Windows, this is at C:\Program Files (x86)\Steam\steamapps\common\Kerbal Space Program. You can also right-click KSP in Steam and select "Manage -> Browse local files." By default, Windows will hide file extensions so you may only see the filename as "KSP" and type "Text Document." That's the right one. It's not in the Logs folder.
The log file is regenerated each time you launch KSP. It is most helpful if you reproduce whatever problem you were experiencing and then grab the log file. Do not restart KSP and then grab the log file while it's still loading (unless it got stuck while loading). It won't be useful.
If your log file is too big for whatever platform you're trying to upload it on, you can compress it first. On Windows, this means right-click and "send to compressed folder."
If your game hard crashed to desktop, the ksp.log file won't have the information about the crash. You need to find the player.log file instead. Its location varies by OS:
- windows:
%USERPROFILE%\AppData\LocalLow\Squad\Kerbal Space Program\(copy-paste this into the address of an explorer window, or press windows key + R and paste it there) - mac:
~/Library/Logs/Unity/Player.log - linux:
~/.config/unity3d/Squad/Kerbal Space Program/Player.log
The bottom of the player.log will tell you the path to the crash report folder where you can find the error.log. On Windows, it's in %USERPROFILE%\AppData\local\temp\squad\Kerbal Space Program\Crashes and then select the most recent folder. The error.log file is very useful to confirm how much memory your system was using at the time of the crash. Most crashes are caused by running out of memory.
Sometimes additional log files will be useful. GameData\ModuleManager.configcacheand Logs\Kopernicus\Kopernicus.log can be helpful in diagnosing some issues. Be prepared to send these if requested.