in UCK Building failed msg shown resolve it

I try to customize a lubuntu 14.04 but it failed . It shows me Please look at /home/aniket/tmp/build.log to see what went wrong.
and I am unable to find it so please help me.
Here is build.log file-
Build (/usr/bin/uck-gui ) started at 2016-09-17 15:58:17
>> Ubuntu Customization Kit 2.4.7 on Ubuntu 15.04, 3.19.0-68-generic x86_64
Starting CD remastering on Sat Sep 17 15:58:17 IST 2016
Customization dir=/home/aniket/tmp/customization-scripts
Removing ISO remastering dir...
Mounting ISO image...
mount: /dev/loop0 is write-protected, mounting read-only
Unpacking ISO image...
Unmounting ISO image...
Mounting SquashFS image...
mount: /home/aniket/tmp/remaster-iso/casper/filesystem.squashfs: failed to setup loop device: No such file or directory
Cannot mount /home/aniket/tmp/remaster-iso/casper/filesystem.squashfs in /home/aniket/tmp/remaster-root-mount, error=32
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
Build ended at 2016-09-17 16:04:18