Linear system solver could not determine the solution

I have a simulation using the EM LF Electro Quasi-Static solver and when I run it I get the error Linear system solver could not determine the solution. I have no idea what the error is.

What is the REASON ERROR that the solver is returning?
The log of the solver is shown below:

[INFO]: iSolve X, Version 5.0.1 (4765), 64Bit Windows
[INFO]: Running MPI version 2.0 on 1 process.
[INFO]: Loading all solver modules:
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\EmFdtdSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\EmLfComplexValuedSolvers.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\EmLfRealValuedSolvers.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\EmLfUnstructuredSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\EmModeMatchingSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\FluidSolverSchur.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\FluidSolverSimple.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\GradientCoilSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\NeuronSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\ScalarSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\SonicSolver.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\ThermalSolverDouble.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\ThermalSolverSingle.x.dll'
[INFO]: Loaded 'C:\Program Files\Sim4LifeLight_v5.0.1.4765\Solvers\ThermalUnstructuredSolver.x.dll'
[INFO]: Simulation 'LF' started on 2020-Feb-06 16:56:16
[INFO]: Solver type: EmLf, ElectroQuasiStatic
[INFO]: Input file name: C:\Users\Dimitris\Desktop\CSF/CSF.smash_Results/27ee99eb-31f4-4be3-bc28-fce65535515e_Input.h5
[INFO]: Input file generated by: Sim4Life light, Version
[INFO]: Output file name: C:\Users\Dimitris\Desktop\CSF/CSF.smash_Results/27ee99eb-31f4-4be3-bc28-fce65535515e_Output.h5
[INFO]: Using Sim4Life light license features.
[INFO]: [2020-Feb-06 16:56:17] Checking out license feature 'QS_SOLVER', expiring the 7-jan-2021, version 5.0, (1).
[INFO]: No additional options set to solver step
[INFO]: Grid size is 110x113x103
[INFO]: Solid settings: frequency = 1000 Hz, characteristic length (worst case domain diagonal) 0.47321
[INFO]:    Epsilon        Mu    SigmaE  QS Approx. Quality  Static Magn. Field    SigmaE/w*Epsilon    Solid name
[INFO]:          1         1         0          9.8362e-11                   0                   0    'Background'
[INFO]:        109         1         2          1.0721e-08           0.0035361          3.2982e+05    'CSF 1  (Head Meshes)'
[INFO]:   1.64e+05         1     0.119          1.6167e-05          0.00021006              12.993    'Brain 1  (Head Meshes)'
[INFO]:    2.7e+03         1    0.0202          2.6581e-07          3.5638e-05              134.07    'Skull 1  (Head Meshes)'
[INFO]:   1.14e+03         1    0.0002           1.117e-07          3.5373e-07              3.1667    'Scalp 1  (Head Meshes)'
[INFO]: Dynamic range is 3.59502e+07 (lower limit solid Background (1) and upper limit solid CSF 1  (Head Meshes) (3.59502e+07)).
[INFO]: Boundary conditions:
[INFO]: X-: dirichlet, (0,0)
[INFO]: X+: dirichlet, (0,0)
[INFO]: Y-: dirichlet, (0,0)
[INFO]: Y+: dirichlet, (0,0)
[INFO]: Z-: dirichlet, (0,0)
[INFO]: Z+: dirichlet, (0,0)
[INFO]: Set fixed potential for GND - base  (Electrode Meshes) with value (0,0)
[INFO]: Set fixed potential for VCC - base  (Electrode Meshes) with value (25,0)
[INFO]: Solid GND - base  (Electrode Meshes): PEC (960 edges)
[INFO]: Solid VCC - base  (Electrode Meshes): PEC (895 edges)
[INFO]: Degree of freedoms: 1316016 total, 1244448 unknowns, 71568 Dirichlet points, 0 collapsed points, 0 unused.
[INFO]: Initialization of grid, dof-handler and boundary conditions.: Current and peak memory usage: 26.48 MB / 40.75 MB (current is 65.0 % of peak)
[INFO]: Computing number of non-zeros
[INFO]: Elapsed time for 'Computing number of non-zeros' was 00:00:00 wall clock time.
[INFO]: Assembling matrix
[INFO]: Elapsed time for 'Assembling matrix' was 00:00:13 wall clock time.
[INFO]: Apply Dirichlet boundary condition
[INFO]: Scaling of Dirichlet point trivial equation is 1.96278e-14
[INFO]: Elapsed time for 'Apply Dirichlet boundary condition' was 00:00:00 wall clock time.
[INFO]: Prepared linear system: Current and peak memory usage: 231.2 MB / 442.5 MB (current is 52.3 % of peak)
[INFO]: Solve linear system with 1316016 = 1.31602*10^6 dofs (degrees of freedom).
[INFO]: Setting up preconditioner
[INFO]: Elapsed time for 'Setting up preconditioner' was 00:00:01 wall clock time.
[INFO]: Setup preconditioner and Krylov solver: Current and peak memory usage: 599.0 MB / 619.1 MB (current is 96.8 % of peak)
[INFO]: Target relative preconditioned residual tolerance is 1e-12, max iterations 100000
[INFO]: Solving linear system
[INFO]: Initial preconditioned residuum is nan (has to drop by a factor of 1e-12)
[INFO]: Elapsed time for 'Solving linear system' was 00:00:00 wall clock time.
[INFO]: Solved linear system: Current and peak memory usage: 599.0 MB / 619.1 MB (current is 96.8 % of peak)
[INFO]: Solver returns: 'REASON ERROR'.
[ERROR]: Linear system solver could not determine the solution.
[INFO]: Solved potential simulation's linear system: Current and peak memory usage: 44.64 MB / 619.1 MB (current is 7.2 % of peak)
[INFO]: EM-Low-Frequency simulation finished with errors.
[ERROR]: Simulation 'LF' failed on 2020-Feb-06 16:56:33
[INFO]: [2020-Feb-06 16:56:33] Released license feature 'QS_SOLVER'.
[INFO]: Peak memory usage: 619.1 MB (649207808 Bytes)
[ERROR]: iSolve framework failed (see previous error messages).

Thank you!