After upgrading from 2.0.8 to 2.1.1, I get the following console error on any component drag in node edit:
TypeError: undefined is not an object (evaluating 'Drupal._lpbMoveErrors.moves.map') builder.js:123
Debugging at that point reveals Drupal._lpbMoveErrors is an array not an object, so there's no moves property. I'm not sure how this is expected to work?
3.0.0-alpha1 has the same error.
Downgrading to 2.0.8 fixes the problem. The equivalent moveErrors method there uses Drupal._lpbMoveErrors.map().
Active
2.1
Code
Removing the offending properties moves and accepts from movesErrors() and acceptsErrors() in builder.js in 2.1.1 results in working drag and drop, but probably isn't the solution.
Drupal._lpbMoveErrors is initially defined as an object with accepts and moves properties, but the properties are not defined by the time it is used in the above, it becomes an array.