My configuration details


Magento version 2.1

Also installed Mbstring extension,

but still getting error

Call to undefined function Magento\Framework\Event\mb_strtolower()

After throwing reindex command,

magento indexer:reindex 
  • after installing mbstring. have you restart apache? Commented Mar 24, 2017 at 12:09
  • yes chirag. I have restarted it Commented Mar 24, 2017 at 12:15

3 Answers 3


If you are using php-fpm you should restart it too, because the new extension is installed but not loaded yet. See similar problem here. You can detect is extension loaded using the phpinfo();: if the extension was successfully loaded you can see something like this:

mbstring extension in phpinfo

To restart php-fpm on ubuntu use the command like:

sudo service php7.0-fpm restart

You can find more info by googling "How to restart php-fpm %your distr%".

  • @MagentoDeveloper I'm glad to help you :) Commented Mar 27, 2017 at 11:02
  • i already installed mbstring but still getting error why?? Commented Jul 24, 2019 at 13:54
  • @prabhakaran7 please, check php version which your web-server using. It is possible that you have many php instances on your server. Commented Jul 25, 2019 at 9:04
  • shared hosting amd php 7.0 Commented Jul 25, 2019 at 9:25

For command line, You have setup a php variable.By which you are running php and magento commands on Command line interface. A php.ini is associated with that particular php variable's php configurations. Please check in that file if php_mbstring.dll is enabled or not. Clear chache and remove generation folder in magento-root/var folder.


Fatal error: Call to undefined function Magento\Framework\Event\mb_strtolower() in C:\Apache24\htdocs\p4p\vendor\magento\framework\Event\Manager.php on line 56

Getting this error while running my project on localhost.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.