Codeigniter session not working

I tried in localhost works but when i uploaded it to my host it doesnt work. I tried to use DB for session it still doesn’t work and when I checked it there was a lot of session created when I refresh my page. In stackoverflow someone suggested to use sess_encrypt_cookie then that’s when i thought something wrong with my host. I tried as well login facebook but that error occurs.

base64_decode() has been disabled for security reasons

This is when I think that I need to change host…