downgrade version?

[gentlemale]

Hello, gents.

After buying this game about a year ago, I can happily say I have enjoyed my time playing this game. So far, I've kept mostly the career mode. 

After browsing the internet for some time, I discovered an interesting mod by the name of "Realistic Solar System" or something of that description. I've watched some videos of people (decidedly younger than me) playing that version, and it interests me quite a bit. Browsing the internet, I found a download link to that version of the game and I think I understand how the download should work.

In the post with the link (which is on this website), it advises to use the 1.3.1 version of the game. I booted my game up and it stated that I was using a 1.8 version.

How can I downgrade my version to one that is compatible with this mod?

 

Thanks in advance for any guidance.

[Cleperli]

If you downloaded the game on the KSP store, you are able to download legacy versions (1.7, 1.6...). I think than version 1.3.1 is available to download. 

[RizzoTheRat]

If it's Real Solar System you mean, its available for 1.7

 https://github.com/KSP-RO/RealSolarSystem/releases/tag/v16.3

[Streetwind]

If you are playing on Steam:

• In your Steam library, rightclick Kerbal Space Program, select "uninstall".
• Afterwards, you might want to go to your Steam install directory, and back up your savegames. They do not get removed by the uninstall. But, if you install an older version, and open these savegames with the older version, they might break. So if you want to keep them, save them somewhere else.
• In your Steam library, rightclick Kerbal Space Program, select "properties".
• Navigate to the "Betas" tab. There will be a dropdown menu. Use it to select version 1.7.3.
• Close the properties window and tell Steam to install the game. You now have an old version that is capable of running the Real Solar System mod.

Bonus tip: KSP does not feature any sort of digital rights management or copy protection. This makes it possible for you to have multiple versions of the game at the same time. For example, before you begin the uninstall process in the list above, you could navigate to your Steam install directory, grab the entire KSP folder, and copy it somewhere else. You can then run KSPx64.exe from that folder, and it will start up just fine. That gives you a separate copy of the current version (1.8.1) that you can play at any time, even while Steam has version 1.7.3 installed.

Many people running mods make heavy use of this. They make a copy of their KSP folder, then install mods into that copy, not into the main Steam folder. This has the advantage that Steam won't automatically install a newer version on top of their modded game when Squad releases an update, which would obviously stop most of the mods from functioning.

 

Edited November 13, 2019 by Streetwind

[Zeiss Ikon]

Second to @RizzoTheRat -- I'm currently running RSS, along with Realism Overhaul and Realistic Progression (RP-1) on 1.6.1, and I'm told the same mod set runs on 1.7.3.

I'd strongly suggest having a completely independent install for a heavily modded game like RSS/RO/RP-1; if you mod the Steam-internal installation, every time Steam updates the game it'll break the whole thing.  As noted, it's not difficult to copy your installed game from where Steam stores it, and after it's copied the copy will be immune to Steam updates, making it (relatively) safe to mod.  Same thing goes for a copy bought direct from the KSP pages -- you can keep multiple installs in different versions, and you'll need to keep the RSS/RO/RP-1 install separate from any others, because generally all mods will affect all saves in a given installation.

Edited November 13, 2019 by Zeiss Ikon

[Kernel Kraken]

Once you do downgrade to 1.3.1, stay there. It's the best.

[Gargamel]

There seems to a few threads you really need to read before you start mucking around with the game files:

 

But to be honest, this really sounds like an XY problem.   You want to play KSP using the "Real Solar System" add-on mod, so you are asking how to downgrade your version of KSP.  Why?  Because the videos you watched were a bit outdated, and the ksp version they were playing, at that time, was the most recent.   But that's not what you are really meaning to ask.   You want to ask, How do I play RSS with KSP at all?

As @RizzoTheRat mentioned, there is a RSS version available for a much later KSP version, with a update to the latest stable KSP probably soon to come.   So I would start looking at the mod you want to play, finding the latest version of that, and then installing the appropriate version of KSP to match. 

If you downgrade to 1.3.1 (which there is nothing wrong with that version, I still play it), then you might have some issues finding all the mod you want to use for that version.   Not all modders have kept past versions available for download, but most have.    I play on my 1.3.1 game because I built my mod set (90 some mods) to be stable then, and then the game moved on.  Going back and trying to build a stable mod set for an old version might be quite tricky for a newbie at modding.  

Check those threads above, they should answer 98% of the questions you have about your dilemma.    

 

Oh, and thread moved to add-on discussion. 

 

[AVaughan]

On 11/13/2019 at 7:23 PM, Streetwind said:

In your Steam library, rightclick Kerbal Space Program, select "uninstall".

Personally, I wouldn't tell Steam to uninstall KSP.  I would just open the steamapps/common directory and drag the Kerbal Space program folder somewhere else.  That means that I still have that install and it's saves available to play if I decide to continue it later, and makes sure that I will get a nice clean install of whatever version I set in the Steam Betas tab.

[Streetwind]

49 minutes ago, AVaughan said:

Personally, I wouldn't tell Steam to uninstall KSP.  I would just open the steamapps/common directory and drag the Kerbal Space program folder somewhere else.  That means that I still have that install and it's saves available to play if I decide to continue it later, and makes sure that I will get a nice clean install of whatever version I set in the Steam Betas tab.

...Yes. If you'll go on to read the second half of my post, you'll notice that I'm recommending exactly that.