I have migrated by Codeigniter based PHP/MySQL application from GoDaddy to AWS EC2 and spent several days to resolve the following error.
Class ‘CI_Controller’ not found.
After trying multiple options, I copied the application files directly from the server and that has fixed this issue.
Previously – I copied the code from the local machine and then imported the database.
In my opinion – database should be imported first and then the files directly from the source server.
If the database is imported after the file migration then there is a high chance of experiencing the mentioned error.