Pump in variable part of mixing circuit

The error message:

This error allows you to keep calculating but is a hydraulic error.

Open

Meaning:

There are 2 pumps which are placed in ‘series’. The error shows up here because the second pump is placed after a mixing valve. When the valve is fully open the pumps are in series

How to solve this error:

It may be that this installation is correct, hence, an accurate check to verify should be done. Otherwise, remove one of the pumps to fix this error.