Read DFU Verion characteristic failed

[hark]

Use SDK 10, SD version is 8.0.

I add the dfu to the ANCS project. Then use the nRF Toolbox App to update the firmware,

but it pop up "Read DFU Verion characteristic failed" as the picture.

[mosi]

I have the same problem. I'm using nRF5_SDK_11.0.0_89a8197.

The DFU app makes the app switch too bootloader mode but then I get this error message.