PETSc error code is: 76 while computing Gradient

[dokken]

You would have to provide a minimal running example, as also stated in

@danny

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

---

*** fenics-support@googlegroups.com

---

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

Read before posting: How do I get my question answered?

Here are a few tips to help get your question answered: Write your message in English. Phrase the title of your post as a question and make it meaningful. Check that your question hasn’t been asked before using the search functionality. Post a “minimum working code example” (MWE) to illustrate the problem: A MWE is the simplest piece of code that reproduces or explains the problem you have. It must be possible to take the MWE, paste it into a file and run it, without any extra modifications.…

Please note that several others have also asked similar questions: Search results for '*** Reason: PETSc error code is: 76 (Error in external library)' - FEniCS Project.