Is there a way to fix this? It only appears in the score and not in the part. Thanks.
What was the instrument before the glock? Was it something with two staves but one of them hidden?
This can sometimes happen when adjusting staff spacing in Engrave mode, though I’m not sure of the exact circumstances under which it happens. You can fix it by selecting a note anywhere in that frame and choosing Engrave > Staff Spacing > Reset Selected Frame. You will need to recreate any staff spacing that you had changed in that frame, but hopefully that will not be an enormous hardship.
Thankyou Daniel, that worked.