★How to retain changes to external reference layers in the main drawing

Issue:

After we modified the layer status of the external reference in the main drawing, when we re-opened the main drawing, we found that the xref-related layer status had not been modified.
So, how to retain the changes to external reference layers in the main drawing?

Causes:

Whether to retain changes to external reference layers in the main drawing is controlled by the system variable VISRETAIN. 

Solution:

Execute the command OPTIONS to call out the Options dialog box and check the option Retain changes to Xref layers under the Open and Save tab. After that, the changes to external reference layers can be retained.