This error occurs when the license is already active on another computer. You must follow the steps below to deactivate and release the license from that PC before it can be activated on another PC.

A full description of this process is available in the DraftSight Community in this Wiki post:

https://r1132100503382-eu1-3dswym.3dexperience.3ds.com/#community:51/wiki:AwKV5cpbQrOLfzbh8t6B7w

If the link does not direct you to the post, copy and paste the link into your web-browser address bar.