Ensure there is a clear line of sight between the remote and the AC unit.
If your remote isn't communicating with your AC unit, you may need to sync it. While most YKR-F 006 models are "point-and-shoot" for AUX brands, follow these steps if it’s unresponsive: ykr-f 006 manual
If the screen is frozen, remove the batteries for 30 seconds. Ensure there is a clear line of sight