You can edit any server behavior created with the Server Behavior Builder, including server behaviors you download from the Dreamweaver Exchange website, and other third‑party developers.
If you apply a server behavior to a page and then edit the behavior in Dreamweaver, instances of the old behavior no longer appear in the Server Behaviors panel. The Server Behaviors panel searches the page for code that matches the code of known server behaviors. If the code of a server behavior changes, the panel does not recognize earlier versions of the behavior on that page.