opening a drawing in Acad LT problem

[charles]

Hi all,

So I have a problem opeing this drawing that i have worked on for quite a while now and all of a sudden this morning

when i tried to open it i got the following message:

"This DWG file was saved by an application that was not developed or licensed by Autodesk. What do you want to do?"

When I continue to open the drawing some stuff is missing from the drawing?

I am using Acad LT 2012 and this drawing was working fine until now.

Any help would be much appreciated

Thanx!

[pendean]

Your file was opened and edited recently in another program: that's all that message says and often that's all it means.
DWG files now have tags/flags that AutoCAD looks for to determine where the file came from (useful to some but mostly it's a marketing tool). I've not seen this flag ever get dropped by AutoCAD itself.

So ask around: someone else touched your file(s) or perhaps just deleted or edited an XREF that is in it (hence the missing content).
OR simply unarchive your files/server backup that you created before you went home last night and use that one.