HOW TO SWITCH THE KSP VERSION?

[AN_HAMSTER_IS_ON_SATURN_V]

Hi kerbonauts,

I am playing with ksp 1.12.* , is there a way to switch between ksp versione?

Like i wanna play 1.5 or old versions for trying old mods not supported by the new versions?

M mean it will be easy and very good to do this similar to games like Minecraft, in that you have a list of evry version when u create an installation

Hope there is a way to do this, feel fre to answer (should be obvious, isn't it?)

Good liftoff everyone!

[Hotel26]

If you've purchased/downloaded via Steam, it can be done.

Steam stores KSP in ~/.local/share/Steam/steamapps/common/Kerbal\ Space\ Program/ [this is on Linux; your miles will vary on Windows]

If you take a (recursive) copy of this while at  any particular version, you can run KSP (by version) separate from Steam.  I, for example, store KSP versions under my ~/env/games/KSP/

For example, ~/env/games/KSP/1.11.2.3077/

Back in Steam, if you right-click the KSP name in your library list of games [from memory, now], you can select a version of KSP to bring down.  You can then make your own separate copy of it, too.  BE VERY CAREFUL ABOUT THIS because it may trash any current saves/ships you have under Steam.  I'd be very sure you are happy with your own independent storage and have played there for a while before attempting the above.

If this does sound a bit too complicated, then by all means, Don't Do It.  Otherwise, proceed At Your Own Risk.

ADDENDUM:
In your KSP directory, find something like KSP.x86_x64 and make a shortcut/launcher to it in order to run KSP.  Set the working directory for the launcher to the same directory^..
(Why?  Because I couldn't run Kerbal Konstructs on Linux for about 5 years due to not doing this!)

Edited April 17, 2022 by Hotel26

[AN_HAMSTER_IS_ON_SATURN_V]

ah, dont worry I am a pc expert and i can copy my ships in desktop folder but...

[Snip]

Edited April 17, 2022 by James Kerman
Redacted by a moderator

[Hotel26]

By the way, @AN_HAMSTER_IS_ON_SATURN_V, welcome to the forum (and your first uptick!).

[GoldForest]

1) Backup any saves or craft files in a separate location than KSP directory
2) Right Click on Kerbal Space Program in Steam
3) Select Properties
4) Click Betas
5) Open the drop down box
6) Select the version of KSP you want
7) Wait for it to download
8) Verify the Download
8A) Repeat steps 2 and 3
8B) Click Local Files
8C) Click "Verify Integrity of game files..." (This is because Steam likes to forget a file or two during download, don't ask why, IDK)
9) Run Verification again, yes, again. Just to be sure. If it says successful, great! Move on. If not, do it again until it does.
10) Congrats, you now have a past version! If you would like to keep this version and others:
10A)  Make a folder on your desktop, or some other location, name it "KSP Installs" or whatever you want. 
10B) Make another folder in that one, name it "1.5.1". 
10C) Copy all files inside the KSP folder into "1.5.1" Folder. 
10D) Repeat steps 2 to 10 to get back to 1.12.3 or any other version you want.
10E) If you want to copy any other versions, repeat steps 2 to 10C