Mbstring error: Uncaught exception Zend_Search_Lucene_Exception

When searching for pages in the search function of TikiWiki, an error can occur stating “Fatal error: Uncaught exception ‘Zend_Search_Lucene_Exception’ with message ‘Utf8 compatible lower case filter needs mbstring extension to be enabled.‘” In TikiWik, this Uncaught exception error also occurs when editing and saving pages. This article will explain how to fix this error on your server.

TikiWiki Error: Uncaught exception “Zend_Search_Lucene_Exception”

The following is an excerpt of the entire error that is thrown.

Fatal error: Uncaught exception 'Zend_Search_Lucene_Exception' with message 'Utf8 compatible lower case filter needs mbstring extension to be enabled.'
in /home/userna5/public_html/tikiwiki/lib/core/Zend/Search/Lucene/Analysis/TokenFilter/LowerCaseUtf8.php:48 Stack trace:
#0 /home/userna5/public_html/tikiwiki/lib/core/StandardAnalyzer/Analyzer/Standard/English.php(37):
#1 /home/userna5/public_html/tikiwiki/lib/core/Search/Index/Lucene.php(23): StandardAnalyzer_Analyzer_Standard_English->__construct()
#2 /home/userna5/public_html/tikiwiki/lib/search/searchlib-unified.php(303): Search_Index_Lucene->__construct('temp/unified-in...', 'en', false)
#3 /home/userna5/public_html/tikiwiki/tiki-searchindex.php(143): UnifiedSearchLib->getIndex()
#4 /home/userna5/public_html/tikiwiki/tiki-searchindex.php(88): tiki_searchindex_get_results(Array, 0, 24)
#5 {main} thrown in /home/userna5/public_html/tikiwiki/lib/core/Zend/Search/Lucene/Analysis/TokenFilter/LowerCaseUtf8.php on line 48

Another instance of this error will be seen when updating the content of a page. The error will say:

Mbstring error in Tikiwiki



· Search index could not be updated. The site is misconfigured. Contact an administrator.
Utf8 compatible lower case filter needs mbstring extension to be enabled.

What causes this Uncaught exception?

This error is caused when the server does not have the mbstring extension installed on the server. What is the mbstring extension? The mbstring extension provides language capabilities for your website. For example, if the site is in Chinese, the mbstring and parse the php code to display the proper characters. In order for TikiWiki to use its search functions, the Mbstring will need to be installed. TikiWiki has a phpinfo page built into the software that can check the php settings for the mbstring.

How to check if the mbstring extension is installed in TikiWiki

TikiWiki has a built in phpinfo page that is easily accessible from the TikiWiki administration. This will explain how to look at your phpinfo through TikiWiki.

  1. Log into your TikiWiki
  2. Phpinfo page in TikiWiki

    Navigate to the Admin link in the menu to the left.

    Click phpinfo.




    The snapshot to the right shows what the mbstring extension looks like when it missing from the phpinfo page.

    Phpinfo page with the MbString


    If the server has the mbstring extension installed, the phpinfo page will look similar to the snapshot to the right.


How to fix the Mbstring

What InMotion Hosting customers can do

Shared business plans should have the mbstring installed by default. If it is not installed on a shared server, systems support will need to fix this. If you are on a VPS or Dedicated server. Our support can install the mbstring extension for you at no charge. In this case you will need to submit a ticket to the support department. If you have root access you can install this through Easy Apache.

What InMotion Hosting customers can do

For those who are not on InMotion Hosting servers, you will want to contact your hosting company to have this installed.


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