Grader gives 0 points despite correct code and shows following message

Course Q&A Deep Learning Specialization Improving Deep Neural Networks: Hyperparameter tun
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1

When creating a post, please aValidateApp | INFO] Validating ‘/home/jovyan/work/submitted/courseraLearner/W1A3/Gradient_Checking.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-a4be88c5c0419ab7

[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/W1A3/Gradient_Checking.ipynb’dd:

  • Week # must be added in the tags option of the post.
  • Link to the classroom item you are referring to:
  • Description (include relevant info but please do not post solution code or your entire notebook)
2

I would suggest a Lab file reset, but keep a copy of your work before you do that!

3

You may be submitting the wrong notebook file, or are using an obsolete version.

4

Yes, there is something structural wrong with your notebook. E.g. maybe you have copied (duplicated) one of the graded cells. Here’s a thread about how to get a fresh copy and then you can “copy/paste” over just your completed code from the “YOUR CODE HERE” segments.