Please e-mail me your DXF so I can see what is wrong, you may have the drawing scale set to inches but the page in mm. T2Laser uses the drawing scale. If you want to cheat I also have overrides available to force conversion to mm in the DXF settings menu.
You may not have had the correct COM port selected, or if you haven't already installed the drivers perhaps that the problem. You can click "Install CH340 Driver" in the Help menu to load drivers, and then make sure you have the laser COM selected and click "Upload Firmware".
@mrmister He's using an older version, that was my first Hatch Fill release and I mentioned in the release notes that some fonts may have that problem due to non-closed points. It was fixed in the next release to automatically close any open points.