error message from spacy training

[mcveigh-h16]

I am encountering an error message when trying to train spacy data. I suspect it's a problem with the training data but am not sure what the issue is. I created the NER labels with (https://arunmozhi.in/ner-annotator/). I then used spacy convert to create the .spacy file from the .json file

python -m spacy convert ./annotations_strain1.json ./

The training command then generates and error

python -m spacy train config.cfg --output ./output --paths.train ./train.spacy --paths.dev ./train.spacy

⚠ Aborting and saving the final best model. Encountered exception:
ValueError('[E986] Could not create any training batches: check your input. Are
the train and dev paths defined? Is discard_oversize set appropriately? ')

I also tried debug and get this
python -m spacy debug data config.cfg --paths.train ./train.spacy --paths.dev ./train.spacy

============================ Data file validation ============================
✔ Pipeline can be initialized with data
✔ Corpus is loadable

=============================== Training stats ===============================
Language: en
Training pipeline:
0 training docs
0 evaluation docs
✔ No overlap between training and evaluation data
✘ Low number of examples to train a new pipeline (0)

============================== Vocab & Vectors ==============================
ℹ 0 total word(s) in the data (0 unique)
ℹ No word vectors present in the package

================================== Summary ==================================
✔ 3 checks passed
✘ 1 error

Any clue on where the problem is? The training data .json is attached and contains many non-ascii characters, I suspect this could be the issue but don't find any documentation on that.

annotations_strain1.json

[mcveigh-h16]

Followup. I tried removing all non-ascii characters which I am sure will help but am still encountering the same error so clearly that wasn't it.