When developing the dfu upgrade device, the code can be loaded to 100%, but the prompt "remote dfu invalid crc error" The compiled firmware can be upgraded with the old nRFtoolbox. We found that the app cannot be loaded when calling DFU-1.6.1 (direct error). However, the library calling DFU-1.1.1 can be loaded but the above error message is displayed. Consult the corresponding version of the DFU library, the device uses S110 V7.10.