I am trying to do a le Bail refinement and the program crashes always and presents the message:

"Unhandled exception in derivatives - Maybe parameter limits would help"

The code is the following:

r_wp 0

xdd R21.xy
x_calculation_step 0.0130

bkg @ 1224.87109` -579.977678` -87.3275927` -331.991463` 87.8573403` 36.5931075`


CuKa2(0.001)
LP_Factor(0)
Radius (240)
Divergence(0.125)
Simple_Axial_Model(@, 10 )
Specimen_Displacement(@, -0.015 )


prm !thick 2 'mm
prm !mu 50 'cm-1
scale_pks = (1 - Exp(- 0.1 mu thick / Sin(Th)));


start_X 3
finish_X 30


xo_Is
xo 12.97
peak_type fp
CS_L(@, 692.12522`)
I @ 5.57102`

xo_Is
CS_L(@, 700 )
Strain_G(@, 0.5)

hkl_Is
lebail 1
phase_name Niquel
space_group "P-1"


a @ 16.825
b @ 19.567
c @ 15.720
al @ 123.70
be @ 68.107
ga @ 121.40

So, where is the mistake?
The second peak has no xo or intensity line. To get things started try deleting both the single peak sections and just have the hkl_Is section.
Thank you very much. That part should not be there!
Thank you very much. That part should not be there!