After PHP upgrade site got fatal error, which led to be icon v extension missing in on the server so after adding this now pages is missing footer and not displaying products properly? s our page is kiernans.ie anyone have any ideas what it could be?

Code: Call to undefined function mb_substr() in /home/foodpack/public_html/app/design/frontend/default/theme281k/template/catalog/product/list.phtml on line 136

  • What is your current PHP version in the server that you recently upgrade? – Supravat M Feb 15 '17 at 10:07

mb_substr() is a multibyte-safe version of substr(), meaning it works with characters as opposed to bytes. This is most noticeable in UTF-8, where many characters are represented by two or more bytes.

According to the installation instructions, mbstring is not a built-in extension. You must enable it by having the appropriate files and configuring PHP correctly. Some information can be found in the link provided, your webhost should be able to help you with the rest.

Find PHP function mb_substr() in your


Throw this into a terminal:

php -m | grep mb

If mbstring shows up then it should work.

Look in your php.ini file. Search for extension= and look through the list of extensions. If there is one with the name mbstring in it then the extension should be installed. If the line is commented out (has a ; in-front of it) then it is not enabled... remove the ;

Restart Apache (or whatever server you are using).

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