  We study the selftrapping properties of an initially localized excitation in
several flat band lattices, in the presence of nonlinear (Kerr) disorder. In
the weak nonlinearity regime, the dynamics is controlled by the degeneracy of
the bands leading to a linear form of selftrapping. In the strong nonlinearity
regime, the dynamics of the excitations depends strongly on the local
environment around the initial excitation site that leads to a highly
fluctuating selfrapping profile. It is shown that the spreading of the
wavefunction in the presence of random nonlinearity, is always completely
inhibited about fifty percent of all cases. The role of degeneracy associated
with the flatbands is explained with the help of the $n$-simplex system, which
can be solved in closed form.
