changing the wate source for irrigation moves from running to error

[Mercedes Gelós]

I have set up my model irrigation using this command and works fine: 

name                     conds      alts      acts       !irrigate 25 mm when plant water stress < 0.8 from aquifer 8 - max 20 times per year using sprinkler
irr_str8_aqu_copy            1         1         1  
var                        obj   obj_num           lim_var            lim_op     lim_const      alt1  
w_stress                   hru         0              null                 -       0.80000         <       !irrigate when plant water stress is less than this value
act_typ                    obj   obj_num              name            option         const        const2                fp  outcome          
irrigate                   aqu         8         sprinkler     sprinkler_med      25.00000      50.00000              null  y  

However, I am coupling the model with GWFlow, and there ist does not work because of the water source, so I just want to change it to unlimited. The problem is that there is an error with this. 

name                     conds      alts      acts       !irrigate from an unlimited source when there is plant water stress
irr_str8_unlim               1         1         1  
var                        obj   obj_num           lim_var            lim_op     lim_const      alt1  
w_stress                   hru         0              null                 -       0.80000         <       !irrigate when plant water stress is less than this value
act_typ                    obj   obj_num              name            option         const        const2                fp  outcome          

irr_demand                 hru         0         sprinkler     sprinkler_ilm      25.00000      20.00000             unlim  y  

Can you help me?

Thank you!