Bug regarding enum field

For an enum field, if we dropdown and select value then some error is coming, but we are typing that same value then error is not coming. Pls tell me solution…

If you don’t spend time with providing more details, nobody will be able (and willing) to help you. You mentioned that that you got an error, wouldn’t you mind to tell us the error message? We may also need to know what you’re doing, if you have any customizations there and so on.