The project which you attached is a bootloader project. For bootloading, you need a bootloadable project. Once you build the bootloadable project, you can pass the generated cyacd file from the Host application after entering the device in bootloader mode and the new firmware gets bootloaded. I don't find any issues with the Bootloader. Can you share your bootloadable project also?
Also - you can check:
AN68272 - PSoC® 3, PSoC 4, PSoC 5LP, and PSoC Analog Coprocessor UART Bootloader
You may try the sample project provided with this AN and see if you are successful in bootloading.