Problem
The following error occurs:
- PHP Fatal error: Uncaught Error: Class ... not found
Cause
This problem often occurs when a Magento extension has not been installed completely, i.e. its dependencies are not fulfilled.
The required libraries have not been installed together with the extension.
Solution
Follow the installation instructions from the Readme file. This can usually be found in the extension package.
The installation should be done with Composer. This will ensure that all required packages and libraries are installed automatically.