kerbowie

Does this affect loading a save e.g. while landed on a planet? I have had problems with landers on the ground immediately exploding and/or jumping into the sky on load.

Quite possibly! I do use that mod and although I don't recall if I used it during the rescue mission, it definitely matches the description:

I did upgrade USI LS via CKAN over the weekend, along with a couple other mods I don't think are related. Other than that, no changes except installing RescuePodValidator. Thanks for the explanation regardless, it doesn't seem like RescuePodValidator can be the root cause of this but I'm still stumped as to what's going on. If it continues I'll try to dig into it and see if I can find a way to reliably reproduce the problem.

I experienced a bug that might be related to this mod, but I'm not sure how I can tell for sure. I went on my first rescue contract and found the stranded kerbal in a pod with no hatch - one of the USI life support pods. I installed this mod at that time but I guess since I had already loaded the pod, it remained where it was and I still had to edit the save file to move the kerbal to my rescue ship. When I returned to the surface and the contract completed, I lost all my other contracts ("completed" and "active" lists were empty and contracts I had previously completed showed up as available, all the way back to "orbit kerbin" etc.) and the kerbal I rescued was nowhere to be found. The only contract I had in "completed" was the rescue mission I just finished. I was able to restore most of the contracts by copying the relevant section from a previous save file, but I did not get the kerbal back. I experienced the exact same thing the next rescue mission I tried. I guess I'll just avoid rescue missions for now. If there's any information I can provide that can help narrow down the cause please let me know, and sorry if this is the wrong place to report this.