# \[BUG-12013\] Concurrent Modification Exception on project load

**URL:** <https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794>\
**Category:** Ignition Early Access\
**Created:** [January 10, 2019, 7:06pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794 "2019-01-10T19:06:36Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![christopher.green](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@christopher.green](https://forum.inductiveautomation.com/u/christopher.green)\
**Post date:** [January 10, 2019, 7:06pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794/1 "2019-01-10T19:06:36Z")

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I am getting a ConcurrentModificationException when trying to open a project after installing the nightly build. It seems to pop up when it tries to start the perspective module.

![](https://us1.discourse-cdn.com/inductiveautomation/original/2X/8/8a5a182ca80fa4e939866dbad52505f1cffc6cc0.png)

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**Author:** ![christopher.green](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@christopher.green](https://forum.inductiveautomation.com/u/christopher.green)\
**Post date:** [January 10, 2019, 7:07pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794/2 "2019-01-10T19:07:25Z")

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To clarify I’m trying to open the designer.

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [January 10, 2019, 7:12pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794/3 "2019-01-10T19:12:40Z")

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Can you click full and give us the whole stack trace?

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**Author:** ![paul-griffith](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/paul-griffith/32/37249_2.png) [@paul-griffith](https://forum.inductiveautomation.com/u/paul-griffith)\
**Post date:** [January 10, 2019, 7:36pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794/4 "2019-01-10T19:36:58Z")

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Looks related to the changes made to get the Perspective module to load. I’ll have a fix up shortly, should hopefully get merged in and into the next nightly.

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<div class="post-metadata">

**Author:** ![christopher.green](https://avatars.discourse-cdn.com/v4/letter/c/b9bd4f/32.png) [@christopher.green](https://forum.inductiveautomation.com/u/christopher.green)\
**Post date:** [January 10, 2019, 8:12pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794/5 "2019-01-10T20:12:08Z")

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java.util.ConcurrentModificationException  
at java.base/java.util.ArrayList$Itr.checkForComodification(Unknown Source)  
at java.base/java.util.ArrayList$Itr.next(Unknown Source)  
at com.inductiveautomation.ignition.designer.IgnitionDesigner.loadProject(IgnitionDesigner.java:903)  
at com.inductiveautomation.ignition.designer.IgnitionDesigner$StartupProjectDialogHandler$1.run(IgnitionDesigner.java:2027)  
at java.base/java.lang.Thread.run(Unknown Source)

Ignition v8.0.0-beta0 (b2019011008)  
Java: Azul Systems, Inc. 11.0.1

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**Author:** ![awalker](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/awalker/32/6874_2.png) [@awalker](https://forum.inductiveautomation.com/u/awalker)\
**Post date:** [January 22, 2019, 10:12pm UTC](https://forum.inductiveautomation.com/t/bug-12013-concurrent-modification-exception-on-project-load/21794/6 "2019-01-22T22:12:42Z")

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This issue was fixed in the build that was uploaded on 1/11. Please let us know if you continue to see this behavior after upgrading.