Problem with upload program via usb dfu

[BWawr]

Hi guys,

I have a problem with updating stm32f407vg disco board via usb dfu, I generate the project from cubemx and I'm looking at the example from ST: en.stm32cubef4\STM32Cube_FW_F4_V1.21.0\Projects\STM324xG_EVAL\Applications\USB_Device\DFU_Standalone , and on this base I want to make the same project but for stm32f407vg disco board. I made everything in the same way, and program compiles without any errors, the dfuse program see my board without problems, but now I made other simply program to just toggle led and now I want to upload it via usb dfu and I get this error: Matching not good. Difference at address 0x0800C004 File byte is 0x7D Read byte is 0x01. In my toggle led program I of course added flash address 0x0800C000 in linker script and correct vector table relocation. I will add my dfu and led toggle program here could you guys look at it or say what could be also wrong ?