console_error.log

26ca748…-vendor.js:41 TypeError: Cannot read property 'toJSON' of undefined
    at N.n.render (26ca748…-duolingo.js:9)
    at success (26ca748…-duolingo.js:3)
    at t.success (26ca748…-vendor.js:5)
    at Object.i.success (26ca748…-vendor.js:5)
    at Object.a (26ca748…-vendor.js:41)
    at O (26ca748…-vendor.js:5)
    at Object.n [as success] (26ca748…-vendor.js:5)
    at c (26ca748…-vendor.js:2)
    at Object.fireWith [as resolveWith] (26ca748…-vendor.js:2)
    at n (26ca748…-vendor.js:4)

response_bad_eca919975fe88042df6b12aebb17e76b.json

{"comment":{"admin_user":false,"watching":false,"translation_language":"en","sticky":false,"topic":{"from_language_name":"English","from_language_abbrev":"en","id":936,"name":"Greek"},"sentence_id":"eca919975fe88042df6b12aebb17e76b","experts":[],"show_tts":true,"translation_id":"b687195c875993d14520f481c13fe4e1","translation":"I put.","category":"general","mod_user":false,"is_forward":true,"title":"\"\u0395\u03b3\u03ce \u03b2\u03ac\u03b6\u03c9.\"","frozen":null,"sentence_comment":true,"sentence_language":"el","word_to_dictionary_url":{"\u03b5\u03b3\u03ce":"/dictionary/Greek/%CE%B5%CE%B3%CF%8E/79806051f0a914005ea56b99188f4a06","\u03b2\u03ac\u03b6\u03c9":"/dictionary/Greek/%CE%B2%CE%AC%CE%B6%CF%89/a0d0806a01dd6f175dd6de0c3a3383f5"},"ldc_sentence_id":"eca919975fe88042df6b12aebb17e76b","all_topics":[],"followers":[],"parents":[{"from_language_name":"English","from_language_abbrev":"en","id":936,"name":"Greek"}],"root":{"from_language_name":"English","from_language_abbrev":"en","id":936,"name":"Greek"}},"has_comment":true,"language":"el","text":"\u0395\u03b3\u03ce \u03b2\u03ac\u03b6\u03c9.","avatar":"//s3.amazonaws.com/duolingo-images/avatar/default_2","id":"eca919975fe88042df6b12aebb17e76b"}

response_good_10d15867cbe43e324f5557b501460f34.json

{"has_comment":false,"is_forward":true,"language":"el","text":"\u03a4\u03bf \u03be\u03ad\u03c1\u03c9.","sentence_language":"el","translation_language":"en","translation_id":"f3d80daab20b4c17e17ecc8c1bb9343f","ldc_sentence_id":"10d15867cbe43e324f5557b501460f34","sentence_id":"10d15867cbe43e324f5557b501460f34","avatar":"//s3.amazonaws.com/duolingo-images/avatar/default_2","sentence_comment":true,"show_tts":true,"translation":"I know it.","word_to_dictionary_url":{"\u03c4\u03bf":"/dictionary/Greek/%CF%84%CE%BF/0f9fcdb020d35f4cd997fc99e244e69e","\u03be\u03ad\u03c1\u03c9":"/dictionary/Greek/%CE%BE%CE%AD%CF%81%CF%89/fb4d9eebe396c2e0f094f97af538b720"},"id":"10d15867cbe43e324f5557b501460f34"}