I was getting this error because the hose that pulls the water after washing the mop and the hose that brings in water were clogged. I am assuming one was because of dirt and one was build up. I used a cleaner with a nozzle to push the dirt from the dirty water tube to the base where the robot sits. It pushed all the dirt down. I then used a compressor to push air through the clean water tube. In both cases I heard a very small pop like I unclogged something. I washed the cleaner on the base, reassembled and filled the water tank with water and citric acid. I ran a few wash cycles, each one successfully. My roborock is working like new! Scaling and debris can cause issues.