I'm running a dev build downloaded last night. Had my first encounter with the no-drag bug. I don't have reproduction steps (going to work on that now), unfortunately, so I expect this data may be useless, but perhaps something here may help in any case. It was an early career first-orbit. I did a de-orbit burn, and time-accelerated through to the atmosphere interface, then re-time-accelerated again until I realize there was no drag. I took a screenshot, and did a quicksave, and let the capsule go around to space again. When I reloaded the quicksave, the drag was still gone. Same a third time. Then I restarted KSP, and tried the quicksave again .... and of course the drag was there. I've uploaded a screenshot and a quicksave while it was happening. There's also a log file, but that was after I restarted, and the bug had gone away. All available here. Plug-ins enabled at the time: ContractConfigurator ContractPacks FerramAerospaceResearch JSI KerbalEngineer KSP-AVC ModularFlightIntegrator ModuleManager.2.6.3.dll NavyFish RemoteTech Squad ThunderAerospace TriggerTech WaypointManager