DWG created by an incompatible version? How to open it
If your CAD program says a drawing was "created by an incompatible version", the file was saved in a newer DWG format than your software can read. You can still view it, print it, or get it converted to your version.
Why it happens
Every few years AutoCAD changes the DWG format. Software can open its own format and older ones, but not newer ones. A drawing saved in AutoCAD 2018 or later (format code AC1032) will not open in AutoCAD 2017 or earlier, and a drawing saved in AutoCAD 2013 (AC1027) will not open in AutoCAD 2012.
Check which format your file is in with the DWG version checker. Then compare it with your software in the DWG versions table.
Five ways to open it
1. View and print it in your browser
The free DWG viewer here reads every format from R14 to the current 2018 format. Zoom, check layers and save each layout as a PDF. Nothing is uploaded.
2. Ask the sender to save it in an older version
In AutoCAD this is File > Save As, then choose an older format under "Files of type", for example "AutoCAD 2013/LT2013 Drawing" or "AutoCAD 2010/LT2010 Drawing". Tell them which version you have.
3. Convert it with a free DWG converter
Free desktop converters can rewrite a DWG in an older format, one file or a whole folder at a time. Keep the original: some newer features may be simplified in the older format.
4. Ask for a PDF or DXF instead
If you only need to look at or print the drawing, a PDF is simpler. If you need to edit it in other software, a DXF in an older version opens in almost every CAD program.
5. Update your software
Any AutoCAD from 2018 onwards opens every current DWG, because the format has not changed since 2018.
Questions
What does "created by an incompatible version" mean?
The drawing was saved in a newer DWG format than the program trying to open it. The file itself is usually fine.
Which AutoCAD version opens AC1032 files?
AutoCAD 2018 and every later version. See AC1032.
Can I open a newer DWG in an older AutoCAD without converting it?
No. The file has to be saved in, or converted to, a format your version supports.