Drawing file is not valid

[solofusion]

Hi I have recieved drawing files via a zip file when I try to open the files each one says "drawing file not valid". I am using the 2004 version of Auto Cad...the drawing symbols are displayed as a regualar Auto Cad file so why are they not opening?! If you have any suggestions please let me know. I have tried opening them by double clicking and by opening Auto Cad first and i get the same result every time...
Thanks in advance for your help!

[lpseifert]

Probably saved in 2007 format. Look here for a converter:
http://usa.autodesk.com/adsk/servlet/index?id=6703438&siteID=123112

[CarlB]

Likely reason is that they are version 2007/2008 drawings. Ask sender to "Saveas" 2004 version, or use Autodesk's TrueView (free download) to convert them.

**edit** I just don't have the speed today :)

[SLW210]

You can also use DWGGateway from Solidworks.

http://www.dwggateway.com/

[ChrisCMU]

I got the same error on a drawing I just got from a client. But, I am using Map 3D 2009, so I'm not sure how this would solve my problem.

Are there any other known causes for the "Drawing File Not Valid" error.

[arqi]

I've had the same problem and i noticed it happens when i downloaded the file to a given folder, then moved the file to another folder and then tried opening it. So what i did was downloaded to any given folder and opened it right away, then do a "save as".

I don't know if i'll work for everyone but why not try it out...good luck