Unable to get the preview of dwg file produced by Solidworks as a sheet metal flat pattern.

I can see preview of all dwg files, and others CAD files also, but I am facing a problem with all the flat pattern produced by Solidworks in dwg format.

I was wondering that why it happens only with Solidworks produced dwg files.

Earlier I was thinking that it may be a problem of autocad. So, I searched the solution on various places including autodesk forum. Where I get some solutions. But nothing works for me.

If anybody have any idea that how to deal with this problem, please let me know. Thanks in advance.