Finding the problem was a bit of a challange. Becuase on the 9 minute rinse cycle, the E-15 code didn't show up, and no water down below. What I had to do was pull the machine out, and take the bottom plate off. Then run a full one-hour cycle to find the leak. And there it was at around 45 minutes. Leaking from the sump to basin seal. I believe that it was only late in the cycle and maybe with heat, that the gasket would allow the water leak.
For the repair, the video did the trick. So well done. The only difference in my Thermador machine was that we have the salt compartment for water treatment.