It seems like a problem in sources list.
I think I changed something in the list.
Here is the problem:

rootakali: # sudo apt-get install zenity
E: Type 'sudo' is not known on line 12 in source list /etc/apt/sources.list
E: The list of sources could not be read.
E: Type 'sudo' is not known on line 12 in source list /etc/apt/sources.list
E: The list of sources could not be read.

Thanks in advance, micovid.