Help algorithm failde at iteration

[Oreste]

The constraints of the model are two, two-dimensional beam elements 8346 is simply supported.
I changed the solver is Umfpack is SparseSPD and gives me the following errors:

UMD2FA: matrix is singular. Only 10945 pivots found
WARNING UmfpackGenLinSolver: solve <void>-4 returned in factorrizazion UMD2FA<>
WARNING AcceleratedNewton::solveCurrenStep<>-
the LinearSysOfEqn failed in solve
StaticAnalysis:: analyze<>-the Algorithm failed at iteration: 0 with domain at load factor 1
returned: -3 error flag

And SparseSPD
!!!pfsfct<>: The diagonal entry 10945 is zero!!!
In SymSparseLinSolver: error in factorizazion.
WARNING AcceleratedNewton::solveCurrenStep<>-
the LinearSysOfEqn failed in solve
StaticAnalysis:: analyze<>-the Algorithm failed at iteration: 0 with domain at load factor 1
returned: -3 error flag

Help me please
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[fmk]

you have a singular system and need more constraints or you need to edit material properties so that they are not zero!