Invalid arx file

[imacad]

Up until today I have been able to attach a PDF file in Autocad Architecture 2011. When I attempted to reload an attached PDF I get the following message:

C:\Program Files\Autodesk\AutoCAD Architecture 2011\acdwfmarkupcore.arx is an
invalid ARX file.
Reload underlay "jessie harris bldg002 - 1": I:\10001.1 UT Jesse Harris
ADA\Drawings\Existing\jessie harris main bldg\jessie harris bldg002.pdf
Unable to reload "jessie harris bldg002 - 1".

And then says unable to load the file and gives possible reasons for not attaching, ie: File is corrupted, created by earlier version, recreate the file in a usable format. The files have been loaded previously and worked fine.

Any suggestions or assistance is greatly appreciated.

[imacad]

Just did a repair of AutoCad and everything is okee dokee again!

[harvestingnow234910]

use a small tool available at to resolve it and render it useable