Uncaught runtime errors

My page is displaying an error "JSON.parse: unexpected end of data at line 1 column 1 of the JSON data" and I don't know how to fix it, the code is the same as the git. Did someone got the same issue?

No file, test, or entry point is named in the issue. Reproduce the page error, inspect the JSON response or input being parsed, and identify the request or data source responsible; done means the page no longer throws this parsing error with the affected data.

索引モデルが issue の本文から書いたものです。