We have an issue with opening drawings received (as email attachments) from one of our consultants. We have two workstations, of similar spec and identical OS, both running identical (I think) versions of AutoCAD
2008. The drawings (also created in AutoCAD 2008 and saved as AC1021/ AutoCAD2007) open fine on Workstation A, but Workstation B throws a "Drawing file is not valid" error.
An audit of the drawings on Workstation A shows no errors and, once resaved, they then open fine on Workstation B.
Any ideas what's going on?