Can’t really answer this question without knowing more information. Was this a new radio or a used one? Did you buy it from a recognized dealer or from a place like eBay? What frequencies are you trying to program into the radio? What software are you using? What cable are you using to communicate with the radio? Have you talked to the radio dealer/seller?
I am assuming you are trying to program amateur (ham) frequencies, and that you know this radio is locked to the following amateur frequencies only:
RECEIVE
- 137-174MHz VHF
- 400-512MHz UHF
TRANSMIT and RECEIVE
- 144-148MHz
- 420-450MHz
If you are trying to enter frequencies outside the amateur radio spectrum (above) it will not accept.