Problem: The client is experiencing a critical error when trying to activate the WPML plugin on their WordPress site. The error message indicates a missing 'DOMDocument' class, which is essential for WPML's operation. This issue persists even after updating PHP, the theme, and trying a default WordPress theme. Solution: We recommend installing the PHP XML extension, which includes the 'DOMDocument' class required by WPML. This extension is often missing in standard PHP installations, especially on custom or minimal server setups. To install this extension, you can run the following command on your server if you have SSH access:
sudo apt-get install php-xml
or for CentOS systems:
sudo yum install php-xml
After installing the PHP XML extension, try activating the WPML plugin again. If the problem persists, it might be due to other incompatibilities. In such cases, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins.
If this solution does not resolve your issue or seems irrelevant, please open a new support ticket at WPML support forum for further assistance.
