I downloaded eDrawings 2018 from the solidworks website, installed it following the instructions, and did not enter a license key for the free version. Double clicked to open an eDrawing file (which was recognized by my computer to be an eDrawing file, judged by the file icon) got the blue wheel mouse pointer for a second to make me think it was firing up, then nothing. Checked the task manager Processes, and nothing was running for eDrawings. Navigated to eDrawings in the Start Menu, tried to launch from there - same thing.
So I uninstalled, restarted, re-downloaded, reinstalled, and restarted. Same exact problem.