How do I find out what the SBT for NIOS error "Downloading ELF Process Failed"?

Thank you for your response. To be more specific, what happens is that I have completely generated the bsp, compiled the software, made the target and recompiled the FPGA. I then program the FPGA and the NIOS2 program runs as witnessed by the USER LEDs flashing. This implies to me that all is well with the Qsys system and the NIOS2. Then for some reason the first time that I try to debug the firmware in the SBT, I get an error that says that the BSP needs to be regenerated which I do. Then the second time that I try to debug the firmware I get the error message in the "Console" that says "Resetting and pausing target processor: FAILED, Leaving target processor paused". I also get a pop-up Error message box that says "Exception occurred during launch Reason: Downloading ELF Process failed". I have checked the "Ignore Timestamp and System ID" boxes in the Run Configuration. I have no idea why I can't debug this firmware that is obviously running upon initial download from the *.sof file. Can you help me figure out what the problem is?