# Nest Field no longer support MemberExpressions

**URL:** <https://discuss.elastic.co/t/nest-field-no-longer-support-memberexpressions/208656>\
**Category:** Elasticsearch\
**Created:** [November 20, 2019, 9:07am UTC](https://discuss.elastic.co/t/nest-field-no-longer-support-memberexpressions/208656 "2019-11-20T09:07:57Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![slayme89](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/slayme89/32/58019_2.png) [@slayme89](https://discuss.elastic.co/u/slayme89)\
**Post date:** [November 20, 2019, 9:07am UTC](https://discuss.elastic.co/t/nest-field-no-longer-support-memberexpressions/208656/1 "2019-11-20T09:07:57Z")

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Hi there!

We are a team that are currently migrating from a 6.4 to a new 7.4 Elastic cluster.  
While upgrading our application to use Nest 7.4 we found a breaking change that is not noted in the current documentation: [Member Expression only](https://www.elastic.co/guide/en/elasticsearch/client/net-api/current/field-inference.html#member-expressions-only)

If a Member Expression is used in the Field constructor in Nest version 7.4, an Exception will be thrown!

The change, that causes this problem can be found here:  
[Github change](https://github.com/elastic/elasticsearch-net/commit/0fb1149c1f84a5e501149c78b222b5ae7dec677c#diff-60957b99fed84039ef5daa9b1861db9f)

We have found a "workaround" for this, by creating a Lambda Expression from a Member Expression before passing it to the Field constructor.

A suggestion is that you either update the documentation or rollback the change 🙂

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**Author:** ![forloop](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/forloop/32/9021_2.png) [@forloop](https://discuss.elastic.co/u/forloop)\
**Post date:** [November 24, 2019, 11:31pm UTC](https://discuss.elastic.co/t/nest-field-no-longer-support-memberexpressions/208656/2 "2019-11-24T23:31:29Z")

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Thanks for raising this @slayme89; would you mind [opening an issue on the GitHub repository](https://github.com/elastic/elasticsearch-net/issues)? I suspect that this constraint might need relaxing further.

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<div class="post-metadata">

**Author:** ![slayme89](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/slayme89/32/58019_2.png) [@slayme89](https://discuss.elastic.co/u/slayme89)\
**Post date:** [November 25, 2019, 2:25pm UTC](https://discuss.elastic.co/t/nest-field-no-longer-support-memberexpressions/208656/3 "2019-11-25T14:25:50Z")

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Hi!

Okey I have now created this: [Github issue](https://github.com/elastic/elasticsearch-net/issues/4240)

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [December 23, 2019, 2:26pm UTC](https://discuss.elastic.co/t/nest-field-no-longer-support-memberexpressions/208656/4 "2019-12-23T14:26:02Z")

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