How to edit save files to remove Mechjeb parts?

[Logan Timmermann]

With this new update of course Mechjeb needs to be updated, but I don't want to use it anymore. Nothing against the mod itself. It is great. I have used it in a lot of my missions. That is my problem now though. It is installed on a lot of the vessels in my save game and I don't want to say goodbye to them as well. 

[overkill13]

You are in luck.  Since Mechjeb parts are radially attached, this will be quite easy.  If you try to do this with inline parts, the attachment nodes make things much more complicated.

First backup your save file.

These instructions will show Kerbal Engineer chip parts, which work similarly to Mechjeb so the screenshots are for examples and WILL NOT match your exact files.

I use Notepad++ for my mm patches and file editing, but this can be done with any text editor.

First you need to find the Mechjeb part for the controller/computer/whatever they call it.  It should be in Kerbal Space Program/GameData/whatever folder Mechjeb goes into/parts/whatever they named to control module part.  Find the .cfg for the part and open it in a text editor.  Should look something like this:

Copy that part name.  Again, it WON'T be EngineerChip for Mechjeb.

Now Open your save directory Kerbal Space Program/saves/the savename and find the latest file with the persistant name, mine was "zKACBACKUP20200215120530-persistent.sfs" because I use Kerbal Alarm Clock, yours might just be "persistant.sfs".  Back it up then open in the text editor.

Search for that part name.  Ignore the first search, that is the part listing under the research tree, it should be fine leaving it alone without causing any issues.  You want to find all the ones that start with PART at the top of the saved section.  See the screenshots below:

Highlight everything starting with and including PART and go all the way down to the operator squigly bracket that lines up with the one directly under PART.  Notepad++ is highlighting the bracket locations in red for ease of reference.  See screenshot:

The next section might not be an ACTIONGROUPS section like mine.  Just for reference, that is the action groups for this vessel, not the part.  And it might not be the same on each vessel. 

Delete that whole section of the file to remove the part.  Now find the next "MechjebChip" or whatever the part name is and do it again until they are all gone.  Save the persistence file and load your save to see if everything still works.  Again, this is fairly easy with radial parts.  Inline parts make this process a real PITA.

Edited February 16, 2020 by overkill13

[jimmymcgoochie]

If you're just using MechJeb as a tool and not using the parts, just uninstall the mod and you'll be fine. Probably. Just back up your most recent save game before you uninstall it and load the game up, just in case.

[Vanamonde]

Thread moved to modded support.