Diagnosis
You want to create a standard recipient list.
All the recipient lists that documents in the current recipient list
appear in, are locked. This is because a document can only be in one
standard recipient list and it should not be possible for two users
to create a standard recipient list for the same document at the same
time.

Procedure
You either have to delete the document from the current recipient list,
or wait until the locked recipient list can be processed again.