The Whirlpool Cabrio F72 error occurs when the control can’t determine if the wash basket has engaged the basket hub or not. This is normally caused by friction on the shaft. The basket should “float” slip up and down on the shaft freely. When it can’t do this the F72 error is reported and the control shuts off the cycle. In some cases you can simply remove the tub and using fine grit sand paper sand/clean the shaft of all the soap scum build up and this will fix the problem. In some cases the shaft is so far gone and gunked up that the entire shaft will need to be replaced which means bearing replacement as well. Below is the bearing kit for that model which includes the shaft.
Here is a video that shows how to do the bearing and shaft replacement for the Cabrio Washer: