Adding label to label tree

[miadonegan-del]

I am trying to add modiolus modiolus species label through WORMS, it says it exists but it wont let me add it . Can anyone offer any advice?

[mzur]

If the "+" button to add the label is disabled maybe the label already exists somewhere else in your label tree? Does the WoRMS query result have a green background? This indicates that the label already exists in the tree.