Nios build tools in Quartus 19.1 for windows will not open. I have no idea to get started to debug this issue. Previous versions of quartus keep crashing on my PC. I've tried installing eclipse mars separately, and that did not help. If I open NIOS II command shell I get this linux like error.
Maybe this post will help you:
Home>FPGA Developers>FPGA Embedded Systems>Nios® II Embedded Design Suite (EDS)
'No templates available after inserting SPOC info file'
Read the installation steps.
I hope it will help you.