error before download in NIOSII

I suggest you click on the "Open Error Log" to have a closer look on what is causing this error message. Generally, this error message can be due to several causes which might include both SOPC hardware as well as Nios II software. Try to narrow down the issue by starting to debug on software side. Benoit's suggestion could be helpful in this case. Open the "Run Configurations" and check the "Target Connection". If everything is okay, then I would say problem caused by SOPC hardware. Perhaps, you might tell us more detailed on your SOPC system for instance, what are the components that make up your SOPC system.