Failure with EKF at px4

Hello everyone!
When I fly a hexacopter coaxial model with gazebo (see my previous topic) the terminal prints for me the next warnings, which I don’t understand quite well. Some of you have the same trouble? As far as I know this failure is given by the sensors (and my personal thought is that my model is not relating well the sensors measurements with the six rotors [ I modified the Iris sdf ]). Some of you could help me?

failure EKF

I solved this long time ago. When the drone has a big amount of rotors, be careful placing them. The mistake was in the motors layout, they were not according to the web layout.

What do you meant with web layout?
can you share the modification?