Description
Due to a problem in the Quartus® Prime Standard Edition version 18.1 update 1 in Windows, you may see this error when creating a new project with Nios® II Software Build Tools for Eclipse.

Resolution
This issue only happens in the Quartus® Prime Standard Edition version 18.1 update 1. To work around it, you can use the Quartus® Prime Standard Edition version 18.1 instead.
This problem is fixed beginning with version 19.1 of the Quartus® Prime Standard Edition Software.