# Unrecognized VM option 'UseConcMarkSweepGC

**URL:** <https://discuss.elastic.co/t/unrecognized-vm-option-useconcmarksweepgc/254534>\
**Category:** Logstash\
**Created:** [November 6, 2020, 1:27pm UTC](https://discuss.elastic.co/t/unrecognized-vm-option-useconcmarksweepgc/254534 "2020-11-06T13:27:46Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![wangqinghuan](https://avatars.discourse-cdn.com/v4/letter/w/d26b3c/32.png) [@wangqinghuan](https://discuss.elastic.co/u/wangqinghuan)\
**Post date:** [November 8, 2020, 6:19am UTC](https://discuss.elastic.co/t/unrecognized-vm-option-useconcmarksweepgc/254534/2 "2020-11-08T06:19:26Z")

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> [@seePyou](#):
>
> `VM option 'UseConcMarkSweepGC`

Jvm option UseConcMarkSweepGC has been removed as of Java 15. You could degrade your JDK.

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_[View the full topic](https://discuss.elastic.co/t/unrecognized-vm-option-useconcmarksweepgc/254534)._