It looks like maybe for some reason Matomo was not correctly installed. In the past these were known reasons for this:

  • The Connect Matomo Integration plugin is installed and configured to run in PHP mode. If that’s the case, we should detect this in the system report
  • The WordFence plugin is causing an issue. A user installed Matomo Beta, uninstalled it, and later installed it again from the WordPress directory and then this error appeared. It was fixed by deleting all the DB entries that contained matomo from these tables: wp_wfKnownFileList and wp_wfFileMods as well as the external_updates-matomo entry from the wp_option table. This error likely only occurred while using the initial beta which was hosted on our servers and then updating the plugin from the WordPress directory. Please let us know if you still experience this issue.

If you still have this issue, please check out the Matomo system report and create a new issue. It be great if you could include the anonymized system report in the issue.

Previous FAQ: How do I fix the error « missing MySQL extension which is required by WordPress » in Matomo for WordPress?