Simpson Esprit 500 Washer Model No. 36S500H01?

Today my wash on Medium Water Level overflowed from the Top all over the floor at the Spray Rinse point, then didn't empty, Spray Rinse or Re-fill, etc. So I did the cycle again to actually rinse my wash on Low Water Level and I didn't have the above problem. Can you tell me whats going on please?