Have you checked ATENA troubleshooting guide, clause 2.4.9?

Please open the Input File (.inp) and look at the line referred in the message (in the
above example, 103). Most likely, you will find there the definition of some function
used for the reinforcement, e.g.,
  xvalues 0.000E+00      1.808110e-02      1.800000e-02      1.818000e-02
Please remember the values on the horizontal axis (x) have to be sorted from lowest to
highest. In this particular case, the strain at yield 1.808110e-02 is greater than rupture
strain 1.800000e-02 (which is an obvious nonsense).
The most probable way this happened: you have entered your function points in
unsorted order. Or, you have changed the elastic part (E, yield) and not updated the
following points accordingly. In any case, please correct the function definition in the
corresponding GiD dialog.
If the line does not belong to a function definition, please check if the line generally
makes sense (see also 2.4.8).