A couple of reasons. Unsupported engine, missing files, corrupt files.
Also, if you read the link again, you will see that it does not affect SQLx, since the same include is used for both SQLite and MySQL, AMXX doesn't load both
I do not browse the forums regularly anymore. If you need me for anything (asking questions or anything else), then PM me (be descriptive in your PM, message containing only a link to a thread will be ignored).