Why is Coinbase not letting me sell?

I've been trying to sell my cryptocurrency on Coinbase, but for some reason, the platform is not allowing me to go through with the transaction. Can you help me understand why this might be happening? Is it a technical issue, or is there some kind of policy that I'm unaware of? I've checked my account balance and made sure that I'm not violating any of the platform's terms of service, so I'm really confused about why I'm encountering this problem. Could you please provide some insight into this issue and let me know what steps I can take to resolve it?