DWG will not open in your laser software? Convert it to DXF first.

A customer, an architect or a colleague sends you a .dwg file. LightBurn will not open it, SheetCAM will not open it, your machine software has never heard of it. The file is fine. DWG is AutoCAD's native format, and almost nothing outside full CAD packages can read it.

Why almost nothing reads DWG

DWG is Autodesk's closed working format. It is binary, undocumented, and it changes with AutoCAD releases. Reading it means licensing a library or reverse-engineering the format, and for a small laser or CAM tool neither is worth it. DXF exists precisely for this handoff: the Drawing eXchange Format is documented and text-based, and it is what nearly every cutting tool actually parses.

So the answer to "how do I open a DWG in LightBurn" is: you do not. You convert it once, and from then on you work with the DXF. People send DWG because it is what AutoCAD saves by default, not because the drawing needs it.

Route 1: the ODA File Converter (free)

The Open Design Alliance publishes a free ODA File Converter for Windows, macOS and Linux. Point it at an input folder, choose an output version and DXF as the output format, and run it. It converts single drawings or an entire folder of customer files in one pass. There is no drawing view and no editing, and that is the point: it does one job without a CAD install.

On the output version: the older ASCII dialects, R12 and 2000, are the ones nearly every laser and CAM importer reads without complaint. Newer dialects allow entity types your importer may not know. One trade-off worth knowing: R12 cannot declare units at all, so the importing program has to be told whether the numbers are millimetres or inches, while the 2000 dialect can carry a unit declaration. If your target tool reads it, 2000 is the better default.

Route 2: any CAD that opens the DWG

If you have access to a CAD program that opens the DWG, the converter is unnecessary: open the drawing and use Save as DXF, with the same dialect advice as above. Often the fastest route is upstream. Whoever sent the DWG almost certainly has AutoCAD or something like it, and exporting a DXF there is one Save As. The consensus on the LightBurn forum is the same: convert first, in whatever tool is closest, and import only DXF.

Conversion does not clean the drawing

A format converter changes the container, not the contents. Whatever problems the DWG had, the DXF now has: text stored as TEXT and MTEXT entities that laser importers skip (see the missing text guide), contours that were never quite closed, splines from fillets, and unit ambiguity that turns into a part 25.4 times too big or too small (the wrong-size guide shows how the scale factor identifies the cause). Architectural drawings add their own noise: dimension lines, hatches and title blocks that you do not want to cut.

Budget five minutes after converting: import, measure one known dimension, and look for missing labels or open shapes before the material goes on the bed.

Where DXF Medic fits

DXF Medic does not read DWG, and it does not pretend to. It reads DXF and SVG, and it is built for exactly the step after the conversion: drop the converted DXF in and it shows the unit the file declares (or the one it assumed, which you can override), measures the gap of every open contour and closes the small ones within your tolerance, removes degenerate leftovers, and names any entity it could not read, TEXT and MTEXT included. That turns "the conversion probably worked" into a list you can act on.