Use editing to correct or complete an update. Use deletion only when the entire entry should be removed.
Deletion is permanent. Linked time and expense entries remain and lose their update link. A linked legacy finance record may prevent deletion. Deleting the narrative is not a way to remove billed work or adjust an invoice.
Your role may allow editing or deleting only your own updates, all visible updates, or neither. You also need access to the update and a case status that permits changes. Closed or read-only cases can block these actions.
If the narrative is correct but a file was linked by mistake, unlink that attachment instead of deleting the whole update.