I have a mixed environment where I have some users are opening .dwg files with DWG TrueView 2011 and others with AutoCad LT 2012. I am able to open the file immediately with DWG TrueView 2011, but with AutoCad LT 2012 they display an error message of "Drawing File Not Valid". In order to view the file I need to go into File>Open> Choose the file located on a mapped drive and select "Open Read-Only". Is there a way this can be changed where I can automatically open files as read only? I have changed the permissions to the share to allow full control to a particular user for testing purposes and it appears that the files are not in read only when examining the properties of it.
Trueview is a viewer that does not need write abilities, AutoCAD is the opposite.
If your file was in a read-only folder or drive, AutoCAD would only open the files in read only.