hi guys i'm using 64bit 2.0 version kali linux

i have problem about remove iceweasel and install firefox

when i use this command i'm getting this error

apt-get remove iceweasel:
Code:
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 gsettings-desktop-schemas : Breaks: mutter (< 3.19.92) but 3.18.2-1 is to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
why is this happeining? this error start to after format

sorry for the language faults