Hello @Imen DAHMEN​ , Thank you for your reply.

I have connected the board with Cube Programmer in Power down mode and performed Full chip erase. After the I have done flashing debugging with no errors. Now the board is properly working.

I have done this in my desktop computer. But when I connecting the board to my linux laptop the problem arises again. Then I need to done the chip erase once again.

Is it a problem related my laptop port? Please let me know.

Thank you.

Sachin