AutoCAD 2010/2011/2012 DWG Format

[#1]

Whenever I have a user that has a problem AutoCAD (crashing, hitching, bombing or weird stuff), many times it's not AutoCAD or their machine, it is the DWG itself.  The drawing can pass through many hands that use either vertical apps or non-autodesk apps to create objects.  My guess is some objects or database gunk bugs AutoCAD for some reason.  I usually prescribe an Audit first, and a good purge plus a -purge of Regapps.  If that doesn't work, then I usually prescribe what I call Dr. CADs Wblock Cure All Elixir.  I have them wblock the stuff they want into another drawing.  They may have to re-xref some stuff and re-insert the title block, but it make the drawing behave much better. 

My question is, why does this work?  Not that I complaining.  Just curious as to what is happening to the drawing when it is wblocked out.

[#2]

If I reach this "if all else fails" situation with a drawing but I can get it open, then I tend to prescribe a dose of DXFOUT, open the DXF and save as DWG. The way my simple brain explains this is that the invalid or corrupt objects have been subjected to a file translator which will not create invalid objects. There might still be a little correction required but they will at least be AutoCAD vailid.

[#3]

WBLOCKing carries across graphical objects, but usually leaves behind any data like group membership, annotation scales, or XDATA/extension dictionaries attached to the drawing itself.  The latter (as well as objects) can contain hard and soft pointers to objects which can become broken if not properly managed - which includes WBLOCK operations.

[#4]

Good to know.  Thanks.  And normally I try to find the root cause first.  But sometimes we get drawings that are very old and/or have been passed around to people using wacky non-Autodesk software.  Usually people simply need to reference in a picture.  I always ask them to save the old drawing as welll.