The following error appears when trying to compute in Darwin Designer:
Feasibility check failed. No feasible solution exists with current input data, for EPS analysis, with time from start >0.00 hrs.
Darwin Designer can be used with an Extended period Simulation (EPS), to design pipes for a certain time-step such as the peak hour (i.e. other than 0.00 hours)
Specifying the 'design time' in Darwin Designer-Forum discussion
Forum discussion-User's case
Can I use Darwin Designer for the EPS analysis?
Using Darwin Designer to design pipes in WaterGEMS