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Common Problems

This page covers known issues that can arise at various stages of Installing and using PHP solutions.

  1. Problem: You may see an error indicating that memory ran out.
  2. Solution: To fix this you will need to increase memory_limit in PHP.ini. By default the size is 128M (128mb). Change this to 256M and try again. If the same error occurs try allowing more memory. See the PHP Manual for more information.

  3. Problem: Plugin install failed because plugin size exceeds the maximum allowed upload size.
  4. Solution: You can bypass this by editing php.ini file by increasing the value of upload_max_filesize directive. After making changes to php.ini your web server (i.e Apache) may require a restart for the changes to take effect. To find php.ini location you can check output of phpinfo();

  5. Problem: Plugin install can not proceed without ftp access.
  6. Solution: The file ownership under Unix-based systems could be the cause. To fix this, run the following terminal commands:

    										chown -R apache:apache path/to/directory

    where -R indicates this should be done recursively and applied to all files and folders in specified directory; apache:apache is the user and group that your web-server processes run under (in Ubuntu this user is usually www-data). Path/to/directory is the path to directory in question.

    Followed by:

    										chmod -R g+w path/to/directory

    This will change permission for the user group to be able to write to specified directory and subdirectory.

  7. Problem: Using theme switcher in Wordpress but not ticking the 'Mobile' box causes the login link to disappear from the website.
  8. Solution: You can login by accessing the and if that does not redirect you to the admin area after you have logged in return to the website and you will see the admin toolbar at the top of the page.

  9. Problem: Entering the license key and pressing "Automatically Update" yields the following message: "The update procedure could not be launched, probably because the server does not support flushing."
  10. Solution: You will need to manually download the Enterprise or Premium device data file from and then upload this file to your Wordpress plugins directory containing the 51Degrees core files (wp_content/plugins/51degreesmobi/51Degrees/51Degrees.dat). Also make sure the name of the Enterprise or Premium data file in your Wordpress 51Degrees plugin folder is 51Degrees.dat , otherwise the plugin will continue using the Lite data file.

  11. Problem: 51Degrees Feature Detection / Image-Resizer or any other component of Wordpress plugin not woking properly in version
  12. Solution: First: download the latest Version 3 of 51Degrees PHP detector from Sourceforge and extract the downloaded archive. Then, in the folder you extracted the files to, copy files contained in the 'core' directory in to your plugin installation directory (replacing existing files) typically located at /wp-content/plugins/51degreesmobi/51Degrees/. This problem is known to affect the enterprise Feature Detection script and in some cases Image Optimiser.