Installation FAQ

From LimeSurvey Manual

Other languages:
Deutsch • ‎English • ‎français • ‎italiano • ‎日本語 • ‎Nederlands • ‎polski • ‎português do Brasil • ‎русский • ‎slovenščina • ‎中文(繁體)‎


Installation on your computer

LimeSurvey can be installed on your computer with MAMP/XAMP or any other system. But your computer is not a web server : it's not accessible via web by other user.

Then if you want to spread your survey on the web : you have to

  • own a server
  • or a web space at a hoster
  • find a LimeSurvey instance specialized hoster
Installation on your computer is not done to share your survey on internet.

Starting installation

How can I create a database and a user in mysql with command line access?

You have to enter the below commands in your mysql.

create database <your_database_name>;

create user <your_database_username>;

create user <your_database_username>@localhost;

set password for <your_database_username> = PASSWORD('<your_database_password>');

set password for <your_database_username>@localhost = PASSWORD('<your_database_password>');

grant all on <your_database_name>.* to '<your_database_username>';

grant all on <your_database_name>.* to '<your_database_username>'@'localhost';

You have to replace <your_database_name>, <your_database_username> and <your_database_password> in above commands with according values.

What if I can't create a database through a script?

Normally, the script creates a new database, and then the table structure. However if your server/ISP doesn't give you admin rights to create a new database in MySQL, you will need to contact your server administrator to create the necessary database (or create it yourself). They should create a blank database for you that gives you the appropriate access rights (ie: read/write/create). Start the LimeSurvey installation as usually and it will then create the tables in the existing database.

Blank page when accessing the Install page

The problem is not with the LimeSurvey installation but with the PHP installation.

  • Verify you have the MySQL PHP module (php-mysql) installed.
  • Verify your PHP install is loading the PHP.ini file your are modifying and not parsing other PHP.INI files on your system.
  • Verify the location and permissions of the following setting in your PHP.ini

  • Verify your server runs a suitable PHP version (e.g. this "blank page" problem appeared with PHP v4.4 and LimeSurvey v2.00+).

Error messages because of non-existing resources

Sometimes files are not uploaded correctly or were broken during upload. This leads to several different error messages. Most of them refer to a file or function within a file which can't be found.

Solution: Re-upload all files using the binary mode of your FTP program.

Requirements page

What is this mbstring (Multibyte String Functions) library?

The mbstring library is a PHP library to be able to convert char sets from one language to another. You need it if you want to run LimeSurvey. To check if it is already installed open the URL


from the web browser. A lot of information will be shown. Search for the string 'mbstring' under the Configuration section.

If you find the mbstring section then all should be well and you can continue on with your LimeSurvey installation!

If you don't find the mbstring section you might have a problem on your hands.

There are three possible scenarios:

  • If it's your providers server: Ask your provider to activate that extension in PHP or how to activate it - if you have a good administration panel for your server you may be able to activate it yourself.
  • If it's your own Linux server: You may have to re-compile PHP and include the mbstring library. Ask the Linux experts how to do that. In most Linux versions today you can install it using your Linux packet manager.
    • If you are using a version of Linux that supports 'yum' (CentOS, RedHat, Fedora):
      1. Use the terminal (as a super user) and type: yum install php-mbstring
      2. Make sure to update /etc/php.ini to update and uncomment the various mbstring params
      3. Make sure to restart apache after installing it: /etc/init.d/httpd restart
  • If it's your own Windows server: Search for php.ini on your system, open it with an editor and search for mbstring. Most probably the line that contains that string is commented out with a semicolon. Remove the semicolon, save and restart your web server.

Stuck at checking file system permissions

If SELinux is activated (primarily on CentOS) then you might get an error that the file system permissions are not correct but the list of directories is empty. SELinux prevents writing even though the permissions are on e.g. 777 or 755. You need to configure SELinux for your server correctly - check out the SELinux documentation.

After database creation

Blank page after database creation


  • LimeSurvey installed OK, and database was created, but instead of the admin page, you get an empty page
  • Web surver log shows "Fatal error: Call to a member function on a non-object in /path/to/limesurvey/admin/login_check.php on line 69"


This is probably an incorrect setting for $rooturl or $rootdir in config.php. In particular, config.php attempts to set $rootdir correctly by calling dirname('''FILE''') and while this usually works, it can be upset when LimeSurvey is installed in a user's home or public_html directory and the home directory is mounted over NFS. Try setting $rootdir manually, and in particular, while your shell or pwd command may show a path like "/disks/hostname/home/username/public_html/limesurvey", try using "/home/username/public_html/limesurvey".

When accessing admin page, the browser keeps running and will eventually fail to show it


  • LimeSurvey installed OK and database was created. But when you access the admin page, the browser keeps running and will eventually fail to show the page.
  • When you check the web server access log, its size has become so big (in some cases, more than 2 GB).
  • Inside the access log, you get this message filling the log.

Warning: fread() [function.fread]: Length parameter must be greater than 0 in /limesurvey/classes/php-gettext/streams.php on line 120

Note: line number may be different depending on your LimeSurvey version.


This may be caused by the mbstring.func_overload setting. Check the setting in your php.ini and set as the following.

mbstring.func_overload = 0

Note: This means no function overloading. See PHP manual for this setting: Function Overloading Feature

When accessing admin page, the browser reports Fatal error: Call to a member function gT() on a non-object in login_check.php on line 76


  • LimeSurvey installed OK and database was created. But when rdirected to the admin page, the browser displayed the the listed error.
  • $rootdir and $rooturl are correctly set in config.php.
  • The disk path name for limesurvey installation directory includes one of the following characters: ()+

Note: Other characters may also induce the same behaviour


Move / rename the limesurvey installation directory so that pathname does not include either the ( or ) characters

After installation

For all issues happening after a successful installation please refer to the Troubleshooting page.