I'm trying to create a simple module which would display a hello world. I have done it before, but now it isn't working anymore. I used the group-office documentation which explain how to create a module and I did the first part exactly how it is explained (creating an empty module). But I still have an error message when I'm going to 'Admin menu->modules' :
An error occurred on the webserver. Contact your system administrator and supply the detailed error.
JsonStore load exception occurred
I really need your help. I tried differents way but it never works.