Description
Due to a problem in the Intel® Quartus® Prime Standard Edition software version 18.1 and earlier, you may see the error message above when you do qsys-generate from the command line which contain PCI Express* The qsys-generate is looking for graphical interface (X server), but it is not present in the command line build script.
Resolution
To work around this problem, download and install “Xvfb”, this tool will act as a virtual frame buffer.
Please take note that Intel does not provide any warranty or guarantee regarding the use of third party software. Hyperlinks to other internet resources are used by you at your own risk.