# XMPP issue

**URL:** https://www.finalbuilder.com/forums/t/xmpp-issue/5905
**Category:** Bugs
**Created:** [June 6, 2014, 4:49am UTC](https://www.finalbuilder.com/forums/t/xmpp-issue/5905 "2014-06-06T04:49:39Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![christian.leh](https://www.finalbuilder.com/forums/letter_avatar_proxy/v4/letter/c/67e7ee/32.png) [@christian.leh](https://www.finalbuilder.com/forums/u/christian.leh)
#### Post date: [June 6, 2014, 4:49am UTC](https://www.finalbuilder.com/forums/t/xmpp-issue/5905/1 "2014-06-06T04:49:39Z")

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Background Monitor&nbsp;  
  
The background process XMPP notification queue threw the following exception: System.InvalidOperationException: Die Auflistung wurde geändert. Der Enumerationsvorgang kann möglicherweise nicht ausgeführt werden.&nbsp;  
bei System.Collections.Generic.List`1.Enumerator.MoveNextRare()&nbsp;  
bei Continua.Notification.Queues.XMPPQueue.Monitor()&nbsp;  
bei Continua.Shared.BackgroundMonitor.Run()  
  
  
after that, i get more errors every 5 seconds until its magically gone after minutes.

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### Author: ![Sparky](https://www.finalbuilder.com/forums/user_avatar/www.finalbuilder.com/sparky/32/10_2.png) [@Sparky](https://www.finalbuilder.com/forums/u/Sparky)
#### Post date: [June 10, 2014, 2:03am UTC](https://www.finalbuilder.com/forums/t/xmpp-issue/5905/2 "2014-06-10T02:03:48Z")

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&nbsp;

Hi Christian,

Thanks for reporting this. I can see a potential concurrency issue in the code which is likely to be the cause of this error. I'll get a fix implemented for the next build.

&nbsp;