The mod is not abandoned, read the last 2 pages of this thread. It is safe to create bases now, you just have to do it in an earlier version than 1.12.1 The latest version of KSP introduced findable bases to add to the launch button and this just interfered with the editing pop up. If you create bases in an earlier version and then import them into 1.12.1 , they actually show up in the launch drop down button. A work around is being researched, but that takes time as the new code has to be gone through and the conflicts identified and then hopefully coded around. It is just 1 aspect that is not turning up at the moment, no need to think it is all over.