# 400 error from \_reindex
**URL:** https://discuss.elastic.co/t/400-error-from-reindex/268926
**Category:** Elasticsearch
**Tags:** reindex
**Created:** [March 31, 2021, 2:54pm UTC](https://discuss.elastic.co/t/400-error-from-reindex/268926 "2021-03-31T14:54:23Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@drdwilcox](https://discuss.elastic.co/u/drdwilcox)
#### Post date: [March 31, 2021, 2:54pm UTC](https://discuss.elastic.co/t/400-error-from-reindex/268926/1 "2021-03-31T14:54:23Z")
I am attempting to use reindex to effect the conversion of a single field from a string to a float. I have run this on several indices without issue, but in my most recent attempt, I get the following error after 29,000 documents have been processed into the new index:
```auto
{
"error" : {
"root_cause" : [
{
"type" : "parse_exception",
"reason" : "request body is required"
}
],
"type" : "parse_exception",
"reason" : "request body is required"
},
"status" : 400
}
```
The mapping is a simple source/dest mapping:
```auto
POST _reindex
{
"source": {
"index": "staging-6.7.1-2021.03.02"
},
"dest": {
"index": "staging-6.7.1-2021.03.02-reindex-time-elapsed"
}
}
```
I can post the definition of the new index, but it is very long. Basically, I took the output from a GET on the source index, removed from the `settings` section anything that wasn't appropriate (provided\_name, creation\_date, etc.) and then changed the data type of the field I cared about. Like I said, this has worked for me.
How can I dig into the source of the 400 error that I am receiving?
Thank you,
Don
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [April 28, 2021, 2:55pm UTC](https://discuss.elastic.co/t/400-error-from-reindex/268926/2 "2021-04-28T14:55:18Z")
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