My leak was caused by the deterioration of the brass flange above the gasket / washer that holds that gasket against the tub basin. The fix was very easy.
1-unplug the unit
2- remove the bottom flashing to access the under side of the unit.
3- unplug the two poles of the heating element.
4-with a 1/2" wrench, remove heating element nuts.
5- remove bottom wash rack and wash arm
6- remove heating element.
7- reverse all steps to install new heater element and element nuts.