# JMS Blocking received returned null **URL:** \ **Category:** Gatling (Open-Source)\ **Created:** [April 20, 2016, 8:32am UTC](https://community.gatling.io/t/jms-blocking-received-returned-null/2943 "2016-04-20T08:32:06Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Patrik\_Mihalcin](https://avatars.discourse-cdn.com/v4/letter/p/d6d6ee/32.png) [@Patrik\_Mihalcin](https://community.gatling.io/u/Patrik_Mihalcin)\ **Post date:** [April 20, 2016, 8:32am UTC](https://community.gatling.io/t/jms-blocking-received-returned-null/2943/1 "2016-04-20T08:32:06Z")
Hi, Under what circumstances Gatling throws **Blocking received returned null?** I found it in the code - [https://github.com/gatling/gatling/blob/master/gatling-jms/src/main/scala/io/gatling/jms/action/JmsRequestTrackerActor.scala](https://github.com/gatling/gatling/blob/master/gatling-jms/src/main/scala/io/gatling/jms/action/JmsRequestTrackerActor.scala), but struggling to understand. Could someone elaborate? Thanks! ---
**Author:** ![slandelle](https://dub1.discourse-cdn.com/flex013/user_avatar/community.gatling.io/slandelle/32/4_2.png) [@slandelle](https://community.gatling.io/u/slandelle)\ **Post date:** [April 20, 2016, 9:25am UTC](https://community.gatling.io/t/jms-blocking-received-returned-null/2943/2 "2016-04-20T09:25:29Z")
[https://docs.oracle.com/javaee/7/api/javax/jms/MessageConsumer.html#receive–](https://docs.oracle.com/javaee/7/api/javax/jms/MessageConsumer.html#receive--) ---
**Author:** ![Patrik\_Mihalcin](https://avatars.discourse-cdn.com/v4/letter/p/d6d6ee/32.png) [@Patrik\_Mihalcin](https://community.gatling.io/u/Patrik_Mihalcin)\ **Post date:** [April 22, 2016, 7:19am UTC](https://community.gatling.io/t/jms-blocking-received-returned-null/2943/3 "2016-04-22T07:19:33Z")
Thanks! Dňa streda, 20. apríla 2016 11:25:31 UTC+2 Stéphane Landelle napísal(-a):