It is due to the clean water tank not being installed or the water level in the clean water tank being insufficient.
If your Xiaomi Robot Vacuum X20+ encounter this problem, please refer to the following troubleshooting steps:
1. Remove the clean water tank and check if the float at the bottom of the clean water tank and the float magnet are in place;
2. If the water level in the clean water tank is not enough to complete the job, an error message will be prompted. Add enough clean water and then tap the power button on the Omni station or in the APP to continue;
3. Re-position the clean water tank and press lightly;
4. If the water tank still reports a fault with water inside, unplug the power of the Omni station, wait for 1 minute, and then plug it back in to retry;
5. If the problem persists, please visit after sales for inspection.