Md9600-csv-2571v5--v26.45.bin -

Flashing this file to the wrong hardware version (e.g., trying to use V5 firmware on a V4 radio) or using it as the main firmware on a handheld instead of just a donor can result in a "black display" or boot loops.

It provides the latest reliable official codec needed for custom firmware functionality.

The MD9600-CSV(2571V5)-V26.45.bin file contains this essential DMR vocoder/codec. The OpenGD77 software relies on this donor file to process DMR audio, while the rest of the radio's interface and features are driven by the open-source firmware. What do the naming conventions mean? Denotes the TYT MD-9600 dual-band DMR mobile radio.

If you accidentally select a different radio's donor file in the OpenGD77 CPS, the software will return an error. You must ensure you use exactly MD9600-CSV(2571V5)-V26.45.bin for the MD-9600 to proceed.

Based on the filename structure md9600-csv-2571v5--v26.45.bin , this appears to be a specifically designed for TyT / Tytera MD-9600 radios (likely the UHF 400-470MHz variant).

Specifies that this firmware is intended for the V5 hardware revision. Using this on V2/V3 hardware can lead to a "bricked" radio. V26.45: The firmware version number. Why Update to V26.45?

You likely flashed a V5 firmware onto an older hardware version. Put the radio back into DFU mode (Step 1) and flash the correct binary matching your hardware.

is what you need to ensure your DMR audio actually works after the flash.