idk if this helps... but ive had that once wehre i needed the first word after the _ to be lowercase
it only occured on deployment servers not localy maybe a mismatch of phpversions?
@phyzical holy moly that worked
Are you developing on (for example) Windows and deploying to a Linux machine?
AH yeah that was it dorset
my case was osx to linux
where osx dunt care about case sensitivity but linux does