NIST databased refrigerants
 

REFPROP_error (203) from function: tprho (density)
[TPRHO error 203] vapor iteration has not converged for T = 300.00 K, P = 3.1680 MPa, rho (last guess) = 6.6230 mol/L, x (mol frac) = 1.00000

I am using R134a as refrigerant and got the this error, What does it mean and how can I sort it out?

Pls suggest me/////

same problem
 

I also using r134a for an analysis...import r134a by activating the NIST real gas using some commands then at the end of solution intialization the same refprop error mentioned above is displaying...anyone suggest me a solution for this problem