One of my colleagues was getting very frustrated with the XREF he was using, he had set up an XREF, turn off the layers as he wanted, then saved and exited the drawing. Upon reopening the drawing he found these changes were reset to the layers on the XREF source.
AutoCAD appears to be setup strangely on my colleagues machine where it prefers to inherit layering from the source. Whilst this is a logical method it doesn’t help new users to understand how to “lock” their XREFs. By default AutoCAD should be in the “locked” mode.
Frustratingly AutoCAD also appears to have no visual way to set VISRETAIN, a toggle for XREF state in the XREF manager would be nice, perhaps a check box with a note next to it saying “Check to retain layer information in current drawing”. That way people will know what is going on!
So its back to the command line, type VISRETAIN and then set to 1 for keeping the layers in the current drawing as you want them or 0 to inherit from source.
From AutoCAD help: (Copyright Autodesk).
The layer table, as stored in the reference drawing (xref), takes precedence. Changes made to xref-dependent layers in the current drawing are valid in the current session only and are not saved with the drawing. When the current drawing is reopened, the layer table is reloaded from the reference drawing, and the current drawing reflects all of those layer property settings.
Xref-dependent layer changes made in the current drawing take precedence. Layer settings are saved with the current drawing’s layer table and persist from session to session.