I have done custom bootloader, it should be jumped to application but it isn't going to jump to the application address, hard fault error is showing up?

[Tesla DeLorean]

Debug normally as you would for a Hard Fault, look at the instructions and registers at the point it faults.

D​etermine if data being read is correct, and addresses are correct. If doing a control transfer that there is viable Thumb code there.

S​tep code transitions in a debugger.

H​ave your HardFault_Handler output actionable data.