Altera Monitor Program cannot load program to De1-SoC

https://alteraforum.com/forum/attachment.php?attachmentid=14669&stc=1 https://alteraforum.com/forum/attachment.php?attachmentid=14669&stc=1 I have been having issues using Altera Monitor Program to load compiled C/Assembly program to the De1SoC board.

It says "could not query jtag instance ids, please ensure the fpga has been configured using the correct .sof file."

However, I am 100% sure it's not due to the .sof file, since I tried both my own .sof file AND the DE1_SoC_Computer.sof files provided by the University Program. It's not due to the C/Assembly program either since I am using the sample files.

Also I don't think it's due to my board/cable since I have no problem uploading the .sof file from Quartus.

(By the way, when I am using Altera Monitor to download/upload the .sof file, it says "The system has been downloaded onto the board, but some JTAG devices could not be queried")

https://alteraforum.com/forum/attachment.php?attachmentid=14670&stc=1

I have been trying to solve it for 2 days, after reinstalling Quartus and the University Program several times, nearly desperate. If someone encountered the same problem before, please help! Thanks!