Invalid files - dwg's do not open

I have backed up several hundred drawings to a NAS drive connected to our server. Now when we try and open the drawings we get a message that says 'Drawing file is invalid'. I have tried copying to desktop and opening direct from the NAS but we get the same error.

Has anybody any ideas what may have caused this? Note other file types seem OK, doc, xls etc

I attach a typical drawing that displays this error.

CCS-259-01.dwg

There has been another post about Invalid files issue within the last few days, you may want to check it out

http://www.cadtutor.net/forum/showthread.php?91927-Not-opening-AutoCad-files-on-Windows-XP-Windows-cannot-find-path-\filename.dwg-quot

Look at the last post in the thread. Not sure if it will help you, but I remembered seeing it.

If you open a drawing file in a text editor programme (like WordPad), the first line of the file is in plain text, and consists AC1024 (the last four numerals are the version of AutoCAD that the file was saved to).

As the first line of your posted file is not plain text, somewhere along the process, the file has been altered and is no longer a valid dwg file.

That file looks awful.

Hopefully you still have the original files somewhere. Those are probably beyond recovery.

See if this helps any http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/AutoCAD-File-Corruption.html

I'm guessing your problem is one of these.

•Network anomalies (transmission errors, file locking, latent writing of data).

•Storage media degradation (bad sectors on a hard drive).

What NAS? I have heard of certain ones that cause problems, usually it is Excel and Word files though.

Are these files being compressed and/or encrypted?

I am not sure, I have an IT guru looking at it at the moment.

Looks like many file types have been corrupted during the backup. This is irony in its purist form!!

That file looks awful.

 

Hopefully you still have the original files somewhere. Those are probably beyond recovery.

 

See if this helps any http://knowledge.autodesk.com/support/autocad/troubleshooting/caas/sfdcarticles/sfdcarticles/AutoCAD-File-Corruption.html

 

I'm guessing your problem is one of these.

 

 

 

What NAS? I have heard of certain ones that cause problems, usually it is Excel and Word files though.

 

Are these files being compressed and/or encrypted?

I have an IT guru looking at it at the moment.

Looks like many file types have been corrupted during the backup. This is irony in its purist form!!

That is funny! Not really, but I find irony funny.