Squashed 'core/' changes from 7884f98..fdeed66

fdeed66 Added a stronger warning message to #154, ready to be merged

git-subtree-dir: core
git-subtree-split: fdeed6660683bd3d845b72f9a88017e9d17b623a
Merge commit '338606d4d04e5d9f4e47b91937b1131558bd5b0a' into bugfix/plugin-conflicts