Drawing file is not valid

[dosx]

Hi, I have a dwg that stated 5,003kb in size but when the file is open its prompt "Drawing file is not valid". How to retrieve it? I try to recover it but nothing happen. Any help, thks in advance!

[michael.12445]

I have seen this message when trying to open a .dwg file that was created in a newer version of AutoCAD than the one I'm using. If this is the case, you can ask the creator of the file to save it down to a version compatible with your AutoCAD.

Autddesk seems to change the .dwg format every 3 releases or so. New formats appeared in R2004, R2007, and I think in R2010.

[rkmcswain]

If drawing version isn't the issue, there are some more things you can check here:
http://cadpanacea.com/node/18

[Coolmo]

Did the file previously open and just now you're getting the problem?

Have you tried INSERTing it into a fresh drawing file to see if it's actually a DWG file?

Did you receive the file from someone else because I've seen where another company (not naming names :?) sent us a file but because it was too big they zipped it into a zip file. Not usually a problem but they some how named the .ZIP file with a .DWG extension. I renamed the file back to .ZIP, unzipped it and BAM! there's the original drawing file.