You can edit the contents of external reference (xref) component views and folders, in-place.
Changes are propagated to all drawing files that contain instances of the xref component or folder. While this is a convenient feature, it also means that if you modify an xref component or folder inadvertently, the mistake is propagated to all drawing files that contain instances of the component or folder. To minimize this risk, you must do one of the following before you edit the contents of an xref component view or folder.
When you turn off the reference lock, geometry from xref component views and folders can be grip edited. When an xref geometry is changed, AutoCAD Mechanical toolset “Locks” the source drawing. This prevents other users from modifying the source while you edit the xref component/folder in-place. On the mechanical browser, components views and folders form the locked source file are flagged by a red lock icon ().
When you activate an xref component view or folder, AutoCAD Mechanical toolset locks the source file of the xref.
Locked source files remain locked until you “purge” all locks or until you close the current drawing.