# Issue 'mautic.NOTICE: RuntimeException: Failed to start the session because headers'

**URL:** <https://forum.mautic.org/t/issue-mautic-notice-runtimeexception-failed-to-start-the-session-because-headers/14254>\
**Category:** Development\
**Created:** [May 10, 2020, 1:26am UTC](https://forum.mautic.org/t/issue-mautic-notice-runtimeexception-failed-to-start-the-session-because-headers/14254 "2020-05-10T01:26:04Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![alexeimolina](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/alexeimolina/32/637_2.png) [@alexeimolina](https://forum.mautic.org/u/alexeimolina)\
**Post date:** [May 10, 2020, 1:26am UTC](https://forum.mautic.org/t/issue-mautic-notice-runtimeexception-failed-to-start-the-session-because-headers/14254/1 "2020-05-10T01:26:04Z")

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[2020-05-10 00:30:04] mautic.NOTICE: RuntimeException: Failed to start the session because headers  
have already been sent by “/var/www/html/plugins/HelloWorldBundle/HelloWorldBundle.php” at line 31.  
(uncaught exception) at /var/www/html/vendor/symfony/http-foundation/Session/Storage/NativeSessionStorage.php  
line 151 while running console command `mautic:dashboard:warm`