[Pkg-otrs-devel] cannot install otrs2 on Debian

[Felipe Ieder]

I'm following this guide : http://docs.google.com/View?docid=drm3kmx_0cbr3x9
The command I execute is : aptitude install --with-recommends otrs2

This is the output of the console :
vps8308:/opt# aptitude install --with-recommends otrs2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Initializing package states... Done
Reading task descriptions... Error!
E: Could not open file /var/lib/aptitude/pkgstates.new - open (2 No
such file or directory)
E: Cannot open Aptitude state file

Any help appreciated, I'm a newbie in Linux.
Thanks!
Felipe