# Transport Error 400 - Failed to derive xcontent **URL:** \ **Category:** Elasticsearch\ **Created:** [February 11, 2015, 8:54am UTC](https://discuss.elastic.co/t/transport-error-400-failed-to-derive-xcontent/22088 "2015-02-11T08:54:29Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![James\_3](https://avatars.discourse-cdn.com/v4/letter/j/45deac/32.png) [@James\_3](https://discuss.elastic.co/u/James_3)\ **Post date:** [February 11, 2015, 8:54am UTC](https://discuss.elastic.co/t/transport-error-400-failed-to-derive-xcontent/22088/1 "2015-02-11T08:54:29Z")
Hi all, I'm trying to run a scrapy crawler to feed elasticsearch but I seem to be getting this error and I can't understand how to begin debugging this. File "/var/www/app/venv/local/lib/python2.7/sitepackages/elasticsearch/connection/base.py", line 97, in \_raise\_error HTTP\_EXCEPTIONS.get(status\_code, TransportError)(status\_code, error\_message, additional\_info) elasticsearch.exceptions.RequestError: TransportError(400, u'Failed to derive xcontent from org.elasticsearch.common.bytes.ChannelBufferBytesReference@a') Can anyone help me on my way to understand what is going wrong and how I might start to debug it? Any help would be appreciated. James -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/1bc780e4-6930-49e4-a24b-6f01a20d51c4%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/1bc780e4-6930-49e4-a24b-6f01a20d51c4%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 12:33am UTC](https://discuss.elastic.co/t/transport-error-400-failed-to-derive-xcontent/22088/2 "2017-07-06T00:33:37Z")