Back office not working

[octb]

Hi,

I am having troubles accessing the prestashop 1.6.1.1 back office. It`s loading for a few minutes and then i get a 404 error.

I tried clearing the cache via ftp with no luck and if I use the "die" function on ADMINFOLDER/index.php the problem seems to appear only at this line:

Dispatcher::getInstance()->dispatch();

I've been using this install of prestashop for years without problem.

The weird thing is that the problem appeared out of nowhere and today it started working for a while (again without changing anything at that certain moment) but stopped after half an hour or so.

Another thing i noticed is that i can still access certain pages from the back office, like the Product Comments module page and some other modules pages. Yet the rest remains inaccessible.

Also, the front office is working without problem.

I contacted the hosting service and they say it's nothing on their part.

Any directions would be appreciated. Thanks!