AutoCAD 2010/2011/2012 DWG Format

[#1]

I am a landscape architect and am having issues with xreferencing the civil engineers contours. They read as rectangles. In the past, I downloaded the OE for civil and installed it and it worked. Now I download the file and when trying to execute, it errors saying there is no associated program that it can install itself to.

Any ideas for me?

[#2]

Are you truly running plain AutoCAD 2011? Is that the default DWG program? Can you start it, close it and try the OE installation again?

Which OE did you download exactly?

[#3]

I had the same issue the other day. What I did is  

1) Options

2) Systems Tab

3) Check "Check Web for Live Enablers"

Hopefully this works for you.