LizardEnterprises

Sure thing. The problem occurs for me due to a bug with lander legs; if you attach lander legs to a fuel tank, that fuel tank will drain into other stages, regardless of what any decouplers have to say about it. The solution is to separate the lander legs from that stage. Adding radial decouplers where you want your landing legs to attach, and then bolting the landing legs onto those decouplers prevents the bug, you just need to remember to check your staging to make sure you don't accidently decouple your landing legs. Someone doing a proper investigation of this bug might want to try using other radial parts like struts, and/or radial parts with toggleable fuel flow toggled on and off, but I have like 3 other bugs I'm trying to figure out before I have time for that. Anywho I hope that helps :-) At the risk of further derailing this thread, I might have a lead for this one. Ive had a few instances where unselected craft in orbit refuse to update any of their orbital characteristics when not-selected. The craft just hangs there in its same position forever, not actually orbiting, just hovering, even though its orbital path is shown. Switching to the stuck craft will usually fix it, but sometimes the fix is incomplete; the craft will update its position and begin moving again, but keep its old orbital velocity... including relative direction of movement to the body its orbiting. This can result in some serious orbital shenanigans as the angle of the orbit no longer matches the crafts position, and a previously circular orbit can suddenly partially, or completely, radially out or in from the planet instead.

So I tried removing the first set of struts and adding struts attached to radial decouplers. I could dock and undock freely in Kerbin orbit, but trying to undock in Munar orbit still caused vessel destruction message. I'll look into another workaround.

Added decouplers to the landing legs. Feul flow problem was fixed. Loss of control problem was fixed. Craft being destroyed on undock was not fixed. Struts are a promising lead. I'll look into it tomorrow, its too late tonight for another test. We might be able to get around this by attaching radial decouplers to both halves of the vessel, and attaching the struts to those? I guess that would depend on how they changed the behavior of struts - they're clearly very different in 2 than they were in 1. Either way, thank you for the heads up, you probably saved me about 10 hours of trial and error :-)

I had an identical issue yesterday using the same mission architecture, and have spent most of today working on tracking this down. I don't yet have a solution or workaround, but I can at least narrow it down somewhat. Here's what I've got: Like you, I built an apollo-style Mun mission, with a LES on top, then Apollo-style CSM assembly, then Munar-lander with separate ascent/decent stages, and then three stages underneath that. Several things bugged out and im not sure which of them are separate bugs, and which of them are the same bug manifesting multiple symptoms. In order of appearance: Fuel drained from the decent stage of my lander when the third-stage engine of my burned, even though they were separated by a decouple. After CSM separation for the Lem+Transfer stage assembly, while controlling the CSM, right clicking on the Lem's docking port did not give me an option to set it as target. Quicksaving and quickloading at that point Does restore the option to target, but Does Not Prevent any and of the other bugs, which appear regardless of whether I quicksave/quickload or dock without targeting and continue the mission. Roll and Pitch control authority on the reaction wheels is lost sometime between the munar transfer burn and arriving in the muns SOI. Yaw continues to work, and RCS and Engine gimbaling still have full freedom of movement on all axes. After munar capture, undocking the craft while not under timewarp results in a vessel destroyed message. Despite this, going to the tracking station shows that the vessel is still there and can be controlled, however the docking ports no longer function at all. If instead, I try undocking *while* under time warp, one or both new craft get a prograde acceleration of about 500 m/s. My first thought was that this was a rare bug involving all docking ports but only affecting me and a small handful of others, so to test this I spent most of this morning building a small orbital station. The docking ports were a little... imprecise? sometimes registering connection when the craft were at very wide angles, or very far apart, but docking and undocking worked without destroying anything, I can therefore rule out a general docking port bug. Im currently testing the lander legs. The feul flow issues with those are pretty bizarre, and seem like an obvious place to test next; Ive read elsewhere in the forum that putting the legs on radial decouples prevents the feul flow issues, so I did that. If it works, I'll see if I still bug out when trying to undock. If I do, I'll build a lander that lands on struts - no legs at all - and see what effect that has. If the bug persists I'll build a CSM version with radial engines so I don't need to flip it around for its transfer burn, and see if its the flipping or the redocking to the same craft you launched on that causes it. Depending how that goes, I'll probably have more station testing to do.

Yes. This is infuriating. After docking a craft, attempting to undock it results in an instant craft-destroyed message. Hilariously, the craft survives under a different name, but the docking ports are now disabled. If you're under time warp during undocking, the craft undocks successfully, however one or sometimes both of the new vessels get several hundred m/s thrust applied. I rebuilt my craft from the ground up on a new save just to make sure it wasn't some weird feature of that particular craft file, issue persists. I hope this issue gets fixed soon as it's severely game breaking; Without functioning docking ports I can't build stations, bases, or even any mission architecture other than direct-ascent. So much for recreating apollo. Other bugs I noticed: Recovered craft do not return their kerbals to the crew roster (RIP Jeb). Despite not choosing the first flag, I somehow got stuck with the first flag? One of my craft, after reverting to launch, randomly lost all control authority on subequent launch attempts. I had to go back to the VAB, remove the main engine, replace it, and relaunch to restore it. Switching craft out of physics range of kerbals on EVA results in... odd behavior. I had two kerbals on EVA and, after switching away and back, they both spawned inside each other, on the ladder of the ship they had previously exited... which proceeded to flip off the ground and crash. I think I'm done for now. The game is beautiful and, aside from the bugs it runs incredibly smoothly for me, but not being able to land on the mun without my craft yeeting themselves into interplanetary space every time I try to undock is a bit of a dealbreaker. I'll try again after the first patch or two gets rolled out.