[Help-glpk] PROBLEM HAS NO INTEGER FEASIBLE SOLUTION

[Paolo Tofoni]

Hi Guys,
can you help me?
I inserted in my model the following constraints:

s.t. k2 {(j,p,m) in V_TECNOLOGICI, (m,k) in FERMI }:
inizio_fermo[m,k] >= start[j,p,m] -  BigP * ( 1 - k1[j,p,m,k] );

s.t. k3 {(j,p,m) in V_TECNOLOGICI, (m,k) in FERMI}:

start[j,p,m] >= inizio_fermo[m,k] - BigP * k1[j,p,m,k];

where

var k1 {(j,p,m) in V_TECNOLOGICI , (m,k) in FERMI} binary;
var start {V_TECNOLOGICI};
param inizio_fermo{FERMI} integer;

and I always obtain the "PROBLEM HAS NO INTEGER FEASIBLE SOLUTION" response.

If I try to drop the above constrains the model runs, if I try to drop individually the other constraints, leaving the above ones, the model doesn't run 
I don't get it why!
Thanks a lot in advance