Well, both V14 and V15 (as well as V16) support (and use by default) the latest DWG version, 2013, is what AutoCAD versions 2013 to 2017 use. You can see the file version by opening it in any text viewer and read the first few characters starting with AC10xx. The versions are as follows: AC1015 = AutoCAD 2000 AC1018 = AutoCAD 2004 AC1021 = AutoCAD 2007 AC1024 = AutoCAD 2010 AC1027 = AutoCAD 2013
So your file is probably corrupted. Did you try to open it with 'Recover' as suggested?
Comments
the message saying:
Unable to load drawing:
Invalid file version
The file seems to be corrupted .
Try using Recover to load the file.
You can see the file version by opening it in any text viewer and read the first few characters starting with AC10xx. The versions are as follows:
AC1015 = AutoCAD 2000
AC1018 = AutoCAD 2004
AC1021 = AutoCAD 2007
AC1024 = AutoCAD 2010
AC1027 = AutoCAD 2013
So your file is probably corrupted. Did you try to open it with 'Recover' as suggested?