'Drawing file is not valid'?!

[kiarianc]

I'm trying to open a series of old AutoCAD dwgs. The date on the files shows as 2001, and they are all AutoCAD Drawing files. But everyone I click on I get the same message 'Drawing file is not valid'.

I've tried recovering drawing, no luck. I also tried changing the file type to DXF to then bring it into CAD, but it's not showing the extension on Explorer.

I'm using AutoCAD 2014. I assume these are older versions, but I still should be able to open them surely?

[ampster40]

I was going to suggest sharing a file so others with 2016 could test - but 2014 and 2016 both save to 2013 by default. Is it possible these files are contained in a database or zip-type file? If either is correct, extract or save down to your local hard drive and try again.

[kiarianc]

Like I said, they are all AutoCAD drawing files. Have the normal AutoCAD Type 'DWG File'. When I right click>properties I get the expected 'DWG File (.dwg). 

Strange one. At least if they were old files they should still at least open, even if the drawing was blank with unreferenced XREFs.

[jggerth]

There are an endless number of things that can go wrong with files being stored for long periods of time -- unless you take the time and spend the money initially to have an archival storage process/medium.  CD-RW deteriorate, disks rot, hec, floppy disks can be erased by the ights in the office.

Best option now is to post one of the problem files, and we can see if anything can be recovered.  After all, just because it says DWG doesn't mean that it really is...

[kiarianc]

I'd like to post a file (would make things a lot easier) but the company I work for won't allow it.
Maybe if I bring in some incense oil to the office, and perform a ritual to the CAD god, the answer will miraculously appear to me!

Yep, hands tied on that point. No can do. Thanks for the advice either way. 

[jggerth]

OK, try this.

Open the supposed DWG file in NOTEPAD, or some other plain ascii editor.

What are the first 6 characters that show up?

then close w/o saving.

[kiarianc]

'n e t   E x p l o r e r \ U R L S e a r c h H o o k s'

Followed by a load of jargon. Does that mean this is not an AutoCAD file after all? If so, why the AutoCAD Dwg icon, and file type?!

[jggerth · Accepted solution]

Yes sir, that's not a valid dwg file.

As to why --- any file can be named anything, by anyone who has access to it.  And the icon that shows up in windows is solely based on the extenstion used in the file name.  Rename it to .xlsx and it will have an Excel icon, whether it's a Word file, a photo, or a real cad drawing.

[kiarianc]

Aha, thank you for your help, and for clearing up the icon issue. I think I knew that (about saving as), but then it's Friday afternoon here, and the brain isn't functioning at 100%. I didn't know about opening a file with notepad to check what type of file it is.

Problem solved.

[Anonymous]

hii 

i have the same problem

i tried to open the file in a notepad and the first 6 characters i get are "AC1021"

so what does it mean ? 

thank in advance

[artc2]

That's what you'd see at the start of an Acad 2007 format dwg file. If you're getting a not valid message when trying to open this file in Acad, then it likely is a corrupt drawing file.

[Anonymous]

yes it's likely a corrupted file 

thank you so much 

[Anonymous]

I'm having a similar issue when trying to open older dwg files. I've opened with notepad and the first 6 are AN#Ø>, was trying to open with AutoDesk 2017 thanks thoughts?

[Anonymous]

my working file yesterday is ok. But today opening time message will coming with window, "Drawing is not valid".i am using auto cad 2014 version.unfortunately i am not enable the temporary back up file option also.so any body help how to get this drawing.drawing have 677694 KB file size showing.

AJITHKUMAR

[Anonymous]

Please help me, the task is in limited time, I must finish my job soon. This morning I ve tried to open my file in. dwg format but theres message that dwg file isn't valid. I have tried to search in google about the problem, but theres nothing.. My file is can't be opened. I 've try to open the file in a notepad but blank..
so what does it mean ? But the file have normally size, 687MB..
thanks guys to help me

[BeKirra]

687mb is not a normal 2d file.

Have you tried to open it with Notepad mentioned in post #6 ?

If so, what is the first 6 characters?

[BeKirra]

---

@Anonymous wrote:
Please help me, the task is in limited time, I must finish my job soon. This morning I ve tried to open my file in. dwg format but theres message that dwg file isn't valid. I have tried to search in google about the problem, but theres nothing.. My file is can't be opened. I 've try to open the file in a notepad but blank..
so what does it mean ? But the file have normally size, 687MB..
thanks guys to help me

---

Sorry, I noticed you have done it with notepad when reading your message again.

And you said it is your file. In this case the file is most likely damaged.

Try "recover" command. Will this fix the problem?

[BeKirra]

And other thought, in worse case, in the same folder you can find the backup file "*.bak" and change to "*.dwg".

You may probably be able to open it.

HTH

[Anonymous]

Hi

Whole week i was working on important file and i am sure I saved it.

Today,when i try to open the same file it says that the drawing file is not valid. I tried open file in notebook but it is blank. Also i tried recovery and recoveryall comand but it doesnt work either. Please help!

[cadffm]

without the file, how?

Use your <filename>.BAK file, it is the second last state of your file.