Please i need assistance on how to resolve the PETScKrylovSolver's Error below

General
1

RuntimeError Traceback (most recent call last)

in <cell line: 8>()
222 # run fenics solver
223 w0.assign(w)
→ 224 it, conv = solver.solve(NLproblem, w.vector())
225 # Extract solution components
226 u, p = w.split()

/content/modelfunctions.py in solve(self, myproblem, x)
347 # iterations
348 if not self.dx.empty(): self.dx.zero()
→ 349 self.krylov_iterations += self.solver.solve(self.dx, self.b);
350
351 # Update solution

RuntimeError:

*** -------------------------------------------------------------------------
*** DOLFIN encountered an error. If you are not able to resolve this issue
*** using the information listed below, you can ask for help at

*** https://fenicsproject.discourse.group/

*** Remember to include the error message listed below and, if possible,
*** include a minimal running example to reproduce the error.

*** -------------------------------------------------------------------------
*** Error: Unable to successfully call PETSc function ‘KSPSolve’.
*** Reason: PETSc error code is: 76 (Error in external library).
*** Where: This error was encountered inside /tmp/dolfin-src/dolfin/la/PETScKrylovSolver.cpp.
*** Process: 0

*** DOLFIN version: 2019.2.0.dev0
*** Git changeset: 1c52e837eb54cc34627f90bde254be4aa8a2ae17
*** -------------------------------------------------------------------------

2

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