Installed Libraries - rebuild cache

Hi all,

We have a WordPress installation with H5P.  In July we transferred WordPress and H5P to a new server. Since then, the exercises didn't work anymore. We get a empty screen. Is it enough to rebuild the libraries cache? Building the cache is a quite long time, is it normal?



Installed Libraries

Not all content has gotten their cache rebuilt. This is required to be able to delete libraries, and to display how many contents that uses the library.

10 contents needs to get their cache rebuilt.

Rebuild cache
icc's picture

This should happen automatically when you visit the exercises.

Could you check your browser's console for any error messages? Ctrl+Shift+J to open it in Chrome.

Hi ,

There aren't any error messages.


thomasmars's picture

Hi Katrien,

It is important when migrating that you include the old libraries (/wp-content/uploads/h5p/libraries) as well as the complete database as a mismatch can lead to inconsistencies that will prevent content from working properly. I tried to reproduce this, but migrating from one server to a new one worked fine here.

If you are using cached assets there may have been introduced inconsistencies during the migration. You can attempt to delete them (/wp-content-uploads/h5p/cachedassets), which will rebuild your cached assets the next time you visit H5Ps.

If there are no errors in your browser console, please check your php error log for any errors that happens when you try to view the H5P ? And just to be clear, all your old H5P content is showing up in the content list, but when you try to view them it is just an empty page ? How does your library admin page look ? Are all the old libraries that you had on your old page still there ?


thomasmars's picture

Hi Katrien,
When installing or re-enabling the plugin you can see the following messages:

Your PHP version does not support ZipArchive.
Your PHP max upload size is quite small. With your current setup, you may not upload files larger than 2.00 MB. This might be a problem when trying to upload H5Ps, images and videos. Please consider to increase it to more than 5MB.
H5P hub communication has been disabled because one or more H5P requirements failed.
When you have revised your server setup you may re-enable H5P hub communication in H5P Settings.

The key message here is "Your PHP version does not support ZipArchive".
Without this extension to PHP H5P is not able to create export files. Disabling the export, "download button", in H5P Settings should make it possible to use most of the functionality of H5P until you have installed the Zip extension for PHP.
Info on enabling the Zip extension for PHP can be found at:

Puede ser útil revisar configuración de php.ini en el servidor.  upload_max_filesize=5M