While trying to navigate through your Kayako Classic instance after installation, you may encounter the PHP Fatal error "Uncaught Error: Call to a member function Assign() on null."
The PHP fatal error you are encountering after the installation (or sometimes during the installation) will typically appear if the Kayako Classic server configuration and system requirements have not been met.
Kindly check to make sure your server environment meets all of the requirements most specifically the following:
- Supported PHP version
- Required PHP modules
- Recommended PHP parameters and configuration in the php.ini file
To verify these pieces of information, navigate to your Admin CP > Diagnostic > PHP Info and do a comparison between what you see in there and the recommendation from the Kayako Classic Server Configuration and System Requirements article.
Please see helpful articles below for installing and upgrading Kayako Classic: