# Error - Cannot read property 'constructor' of null while using Neovis.js

**URL:** <https://community.neo4j.com/t/error-cannot-read-property-constructor-of-null-while-using-neovis-js/2456>\
**Category:** Cypher\
**Tags:** cypher, operations, import\
**Created:** [October 15, 2018, 7:00am UTC](https://community.neo4j.com/t/error-cannot-read-property-constructor-of-null-while-using-neovis-js/2456 "2018-10-15T07:00:38Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![lyonwj](https://sea1.discourse-cdn.com/flex021/user_avatar/community.neo4j.com/lyonwj/32/27358_2.png) [@lyonwj](https://community.neo4j.com/u/lyonwj)\
**Post date:** [October 15, 2018, 12:44pm UTC](https://community.neo4j.com/t/error-cannot-read-property-constructor-of-null-while-using-neovis-js/2456/2 "2018-10-15T12:44:01Z")

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I'm not certain, but it looks like neovis.js may not be properly handling nulls returned in the Cypher query as a result of using `OPTIONAL MATCH`.

Could you please create a Github issue here and we will investigate further and fix: [Issues · neo4j-contrib/neovis.js · GitHub](https://github.com/neo4j-contrib/neovis.js/issues)

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