Encountered the same issue after an upgrade; from the Dassault DraftSight User Forum:
Regarding your issue, can you please try the following steps and see if any helps:
-Try Restarting DraftSight with default settings:
a. Close DraftSight, go to location: ‘C:\Users\[username]\AppData\Roaming\DraftSight’
(If you cannot find 'appdata' folder as it is hidden sometimes, search %Appdata% on the location panel).
b. Right click the folder’ DraftSight’ and Rename the folder to ‘DraftSight_Old’
c. Restart DraftSight. DraftSight should now open with default settings.
This worked for me, but a warning. You will loose all custom modifications specifically the Ribbon UI. I discovered you can recover the Ribbon UI mods by copying the Workspace and UI directories from your _OLD directory into the recreated Draftsight directory. Make sure Draftsight is closed before you copy, and overwrite existing.