In latest 1.10 release, Mk2 Lander Can doors don't work: it can be easily fixed with a single ModuleManager patch:
Put this text in a new *.cfg file anywhere under GameData, and restart the game. This will fix ships in flight too. This patch should disable itself when the bug will be fixed, so it'll be ok to forget to remove the file.
Make sure you have ModuleManager installed too.
I posted a report on the bug tracker here: https://bugs.kerbalspaceprogram.com/issues/25703