Due to a problem with the Intel® Quartus® Prime Software version 15.1.2 and later the Low Latency 10G MAC Example, Design may fail to generate on Windows®.
This problem can happen if the required Windows Environment settings are not correctly set during the Quartus Prime installation.
To work around this issue manually, make or ensure that the following windows environment variables are set on your system:
User Variables
Path : <your install location>\modelsim_ae\win32aloem;
QSYS_ROOTDIR : <your install location>\quartus\sopc_builder\bin
QUARTUS_ROOTDIR : <your install location>\quartus
System Variables
Path : %QUARTUS_ROOTDIR%\bin;%QSYS_ROOTDIR%
QSYS_ROOTDIR : <your install location>\quartus\sopc_builder\bin
QUARTUS_ROOTDIR : <your install location>\quartus
SOPC_KIT_NIOS2 : <your install location>\nios2eds
Please also refer to this related solution, rd03282016_423.