Title: Cannot Activate
Last modified: August 22, 2016

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# Cannot Activate

 *  Resolved [jacobjavits](https://wordpress.org/support/users/jacobjavits/)
 * (@jacobjavits)
 * [11 years, 5 months ago](https://wordpress.org/support/topic/cannot-activate-16/)
 * When I install the plugin and try to activate it, I get the following error message:
   
   Warning: require_once(__DIR__/PdfThumbnailsPlugin.php) [function.require-once]:
   failed to open stream: No such file or directory in /htdocs/website/wp-content/
   plugins/pdf-thumbnails/pdf-thumbnails.php on line 10
 * [https://wordpress.org/plugins/pdf-thumbnails/](https://wordpress.org/plugins/pdf-thumbnails/)

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Plugin Author [stianlik](https://wordpress.org/support/users/stianlik/)
 * (@stianlik)
 * [11 years, 5 months ago](https://wordpress.org/support/topic/cannot-activate-16/#post-5557486)
 * This may be caused by an outdated server setup. The `__DIR__` constant is not
   supported for PHP versions older than 5.3. Can you check which version you are
   running?
 * I just releasted a new version that should be backward compatible with PHP 5.2.
   Please update to version 0.0.5 and let me know if it works. Thanks.
 *  Thread Starter [jacobjavits](https://wordpress.org/support/users/jacobjavits/)
 * (@jacobjavits)
 * [11 years, 5 months ago](https://wordpress.org/support/topic/cannot-activate-16/#post-5557559)
 * The new version activated with no problems…thanks!

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Cannot Activate’ is closed to new replies.

 * ![](https://s.w.org/plugins/geopattern-icon/pdf-thumbnails.svg)
 * [PDF Thumbnails](https://wordpress.org/plugins/pdf-thumbnails/)
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 * [Unresolved Topics](https://wordpress.org/support/plugin/pdf-thumbnails/unresolved/)
 * [Reviews](https://wordpress.org/support/plugin/pdf-thumbnails/reviews/)

 * 2 replies
 * 2 participants
 * Last reply from: [jacobjavits](https://wordpress.org/support/users/jacobjavits/)
 * Last activity: [11 years, 5 months ago](https://wordpress.org/support/topic/cannot-activate-16/#post-5557559)
 * Status: resolved