# Install Fatal Error

**URL:** https://forum.mautic.org/t/install-fatal-error/5665
**Category:** Product Support
**Created:** [March 18, 2016, 4:28pm UTC](https://forum.mautic.org/t/install-fatal-error/5665 "2016-03-18T16:28:09Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![Dominique](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@Dominique](https://forum.mautic.org/u/Dominique)
#### Post date: [March 18, 2016, 4:28pm UTC](https://forum.mautic.org/t/install-fatal-error/5665/1 "2016-03-18T16:28:09Z")

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Hi all,  
  
  
  
When I try to install Mautic on my mutual host, i’ve got this message at the end :  
  
  
  
Fatal error: Call to undefined function MauticCoreBundleHelperopcache\_invalidate() in /home/imaginerqo/www/mautic/app/bundles/CoreBundle/Helper/CacheHelper.php on line 160  
  
  
  
The site is offline.  
  
  
  
My Php version is 5.6  
  
My Sql version is 5.5  
  
  
  
Could you help me please ?  
  
  
  
Regards,

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### Author: ![Dominique](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@Dominique](https://forum.mautic.org/u/Dominique)
#### Post date: [March 18, 2016, 4:28pm UTC](https://forum.mautic.org/t/install-fatal-error/5665/2 "2016-03-18T16:28:09Z")

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Hi all,

When I try to install Mautic on my mutual host, i’ve got this message at the end :

Fatal error: Call to undefined function MauticCoreBundleHelperopcache\_invalidate() in /home/imaginerqo/www/mautic/app/bundles/CoreBundle/Helper/CacheHelper.php on line 160

The site is offline.

My Php version is 5.6  
My Sql version is 5.5

Could you help me please ?

Regards,

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### Author: ![Dominique](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@Dominique](https://forum.mautic.org/u/Dominique)
#### Post date: [March 21, 2016, 9:19am UTC](https://forum.mautic.org/t/install-fatal-error/5665/3 "2016-03-21T09:19:25Z")

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up

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### Author: ![ninjoan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ninjoan/32/1005_2.png) [@ninjoan](https://forum.mautic.org/u/ninjoan)
#### Post date: [March 21, 2016, 2:51pm UTC](https://forum.mautic.org/t/install-fatal-error/5665/4 "2016-03-21T14:51:49Z")

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@Dominique try to delete the folders inside Mautic/App/Cache  
thend reload the page.

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### Author: ![Dominique](https://avatars.discourse-cdn.com/v4/letter/d/e99b99/32.png) [@Dominique](https://forum.mautic.org/u/Dominique)
#### Post date: [March 21, 2016, 5:01pm UTC](https://forum.mautic.org/t/install-fatal-error/5665/5 "2016-03-21T17:01:05Z")

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It works ! Thanks a lot!

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### Author: ![ninjoan](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/ninjoan/32/1005_2.png) [@ninjoan](https://forum.mautic.org/u/ninjoan)
#### Post date: [March 21, 2016, 7:00pm UTC](https://forum.mautic.org/t/install-fatal-error/5665/6 "2016-03-21T19:00:29Z")

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Cool! @Dominique