This is almost always a driver issue. Try a different USB port or roll back your Prolific driver to an older version (3.2.0.0 is often the most stable for radio cables).
File name clue: The software is often packed as HYT_TC-508_CPS_Setup_v6.03.zip . The size is typically 15-30 MB. If it is 2 MB, it is likely a driver-only package or malware. Hyt Tc-508 Programming Software Download
Disclaimer: Ensure you have the appropriate FCC or local regulatory licenses to make changes to radio frequencies. Hytera TC508 Customer Programming Software & Firmware This is almost always a driver issue
Ensure you download a version compatible with your region (e.g., North American versions). The latest widely used version for RDA Narrow Band is V5.05.01 or V5.06 . 2. Required Hardware for Programming The size is typically 15-30 MB
The specific software for the TC-508 is usually labeled as the Customer Programming Software (CPS) for the HT500 or TC-500 series. How to Download and Install the Software 1. Finding a Reliable Download Source
Turn the radio on and set the volume to about 50%.
It is standard practice to read the current data from the radio and save it as a backup file before attempting to write new settings.