I have a Baumatic Suprema1W/SS - several years old but am currently getting Error 4 alarms part way through the cycle. This is a free standing unit.
There are many comments in previous correspondence concerning removing black plastic panels and mopping drip tray--- However my unit has no black panels and I wonder if there is another access on this model to the drip tray and float switch !!!

Tim, January 2015

The black plastic panels are behind the lower plastic trim below the door. Take that trim off, remove the black plastic panels and then get your hand in there with a sponge to mop up any water. Make sure power is switched off at wall plug before doing so. Another way is to tip dishwasher backward as far as possible & allow any water to come out of tray on to floor. Have some towels ready to catch the water.

Lincoln Appliance NZ, January 2015