Hello, I've been trying to install Extensions to my flarum, and even though I reinstall from zero, clearing up the cache and everything I'm still presenting the following issue:

I think It's important to clarify the following:
- It doesn't happen only with Flagrow Extension, i've tested a few others and I get the same thing.
- I use PHP 7.0 and CentOS 7.1
- I have installed flarum in a subdirectory and already changed the nginx config to redirect to the specific subdirectory.
- I am having the last Flarum beta release.
Have everyone a great day and hope you guys can help me!