Realist

Hi guys  🙂
I’ve tried to solve this the whole day, but I can’t get through it.
I’m stuck on a substr() warning given as ouput by using LFI.
I wanted to give a look at the source code, but I can’t find cmsimple 3.0 anywhere, only the latest version.
The latest version’s source code understanding is enough to solve this challenge? Or I’m trying to solve this the wrong way?

Actually solved it, the actual hint is percivable even by the latest version =)