You encounter this kind of error "Cannot redeclare class ..." even though you already used the
require_once to make sure that you include the file only once. What!?
The problem is, there's a chance that the
path that being included has different character cases from the physical file on the system. (Due to case sensitivity)
For example (The actual file is
# if you somehow run this require_once again. It will shows the error above
So, make sure you have the correct file name before execute the