2011: Slow xref selection in External References paletteIssueSelecting xrefs in the External References palette is slow when working in large or complex drawings. SolutionStarting with the AutoCAD 2011 release, selecting an xref in the External References palette automatically highlights the corresponding referenced objects in the drawing window and vice versa. This makes it easy to identify xrefs however, in complex drawings, the highlighting of the xrefs can slow the selection process. This behavior is controlled by the ERHIGHLIGHT system variable. Setting ERHIGHLIGHT to 0 will prevent referenced objects from being highlighted when the reference name is selected in the External References palette. 
Figure 1: ERHIGHLIGHT = 1
Figure 2: ERHIGHLIGHT = 0
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