Forgot the crockpot lid
Yes. Crockpots are carefully calibrated to come to temperature quickly in the beginning of cooking (this is why they need to be 1/2 to 3/4 full of liquid). Without the lid on it would not come to a safe temperature and you will be at risk of foodborne illness if you eat the chicken or serve it to someone. Sorry! I know that's frustrating to waste good food, but it's better safe than sorry.