Fluid is no longer in the vapor phase because the fluid temperature/pressure is...

A Warning message in AFT xStream

Full Message is:

Fluid is no longer in the vapor phase because the fluid pressure is above the Saturation Pressure for the following...

The solution indicates that the temperature and pressure conditions at the specified pipe are such that one or more gas components has reached saturation conditions. xStream will attempt to extrapolate gas-phase properties beyond saturation conditions because xStream assumes the fluid is single-phase. Optionally, the user can choose to limit properties to Saturated Conditions in the Advanced Transient Parameters panel.

Results from the MOC Transient after the transient temperature and pressure reaches the saturation temperature and pressure should be treated with caution.