The system lacked effectiveness on cloudy nights, the range of the  radar [] was too short and it could not Identify friend or foe, which led occasionally to attacks on friendly night fighters; some night fighter crews disliked ground control for the loss of flexibility.
The text describes a radar system that struggled in certain conditions, causing issues with identification and resulting in potential friendly fire incidents. Night fighter crews found the ground control's limitations frustrating due to the reduced flexibility it provided.