@Markiyan Hirnyk 

This is another problem that we had and we keep getting this error please help.

Error: 

Error, (in dsolve/numeric/process_input) invalid specification of initial conditions, got 0 = 0.1e-1

> restart;
>with(DEtools);

L := -4.80; MU := 0.1e-2; DE13 := {(D(x))(t) = y(t)*(1-y(t)*y(t))+MU*x(t)*(x(t)*x(t)-3*y(t)*y(t)-L), (D(y))(t) = -x(t)*(1-2*x(t)*x(t))+MU*y(t)*(x(t)*x(t)-3*y(t)*y(t)-L)}; DEplot(DE13, [x(t), y(t)], t = -20 .. 20, [[x(0) = 0.1e-1, y(0) = .99], [x(0) = 0.1e-1, y(0) = .95], [x(0) = 0.1e-1, y(0) = .9], [x*0 = 0.1e-1, y(0) = .96]], stepsize = 0.1e-2, scene = [x(t), y(t)], title = "phaseplane plot", linecolor = black, thickness = 1);