When working with locked elements, the ability to add connectors depends on the locked status of the source and target elements. The rules are:

That is, a connector can be added if its source is unlocked, regardless of the locking state of the destination (think of it as modifying what the source can see). The exception is composition connectors, where the target (i.e. parent) must be unlocked (think of it as modifying the parent by adding children).

See Also