Grader Error: Week 1 Initialization Assignment

For the Initialization Assignment (Week 1) I believe there’s an error validating my notebook for submission. In my notebook, all tests pass. But, when I submit it to the grader I get a score of 0/100. I have updated my notebook and refreshed it to no avail. Here’s the error my grader keeps throwing:

[ValidateApp | INFO] Validating ‘/home/jovyan/work/submitted/courseraLearner/W1A1/Initialization.ipynb’
[ValidateApp | ERROR] Traceback (most recent call last):
File “/opt/conda/lib/python3.7/site-packages/nbgrader/preprocessors/checkcellmetadata.py”, line 11, in preprocess
MetadataValidator().validate_nb(nb)
File “/opt/conda/lib/python3.7/site-packages/nbgrader/nbgraderformat/v3.py”, line 107, in validate_nb
raise ValidationError(“Duplicate grade id: {}”.format(grade_id))
jsonschema.exceptions.ValidationError: Duplicate grade id: cell-f5d0f829aa0eb6ff

[ValidateApp | ERROR] Notebook failed to validate; the nbgrader metadata may be corrupted.
[ValidateApp | ERROR] Traceback (most recent call last):
File “/opt/conda/lib/python3.7/site-packages/nbgrader/apps/validateapp.py”, line 72, in start
validator.validate_and_print(filename)
File “/opt/conda/lib/python3.7/site-packages/nbgrader/validator.py”, line 340, in validate_and_print
results = self.validate(filename)
File “/opt/conda/lib/python3.7/site-packages/nbgrader/validator.py”, line 311, in validate
nb = self._preprocess(nb)
File “/opt/conda/lib/python3.7/site-packages/nbgrader/validator.py”, line 290, in _preprocess
nb, resources = pp.preprocess(nb, resources)
File “/opt/conda/lib/python3.7/site-packages/nbgrader/preprocessors/checkcellmetadata.py”, line 16, in preprocess
raise ValidationError(msg)
jsonschema.exceptions.ValidationError: Notebook failed to validate; the nbgrader metadata may be corrupted.

[ValidateApp | ERROR] nbgrader encountered a fatal error while trying to validate ‘submitted/courseraLearner/W1A1/Initialization.ipynb’

Solved by @jus_kenny. He updated the notebook and redid the assignment.

Good luck with the rest of the course!