unable to delete partitions

[Michal Dziczkowski]

while attempting to remove a partition, I recieve following error messages:

== start ==

Error deleting partition /dev/sdc2: Command-line `parted --script "/dev/sdc" "rm 2"' exited with non-zero exit status 1: Warning: /dev/sdc contains GPT signatures, indicating that it has a GPT table. However, it does not have a valid fake msdos partition table, as it should. Perhaps it was corrupted -- possibly by a program that doesn't understand GPT partition tables. Or perhaps you deleted the GPT table, and are now using an msdos partition table. Is this a GPT partition table?
Error: The backup GPT table is corrupt, but the primary appears OK, so that will be used.
Warning: Not all of the space available to /dev/sdc appears to be used, you can fix the GPT to use all of the space (an extra 6307840 blocks) or continue with the current setting?
Error: Unable to satisfy all constraints on the partition.
 (udisks-error-quark, 0)

== end ==

NOTE: this file may have a included report from apport

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: gnome-disk-utility 3.10.0-1ubuntu3
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic i686
NonfreeKernelModules: wl
ApportVersion: 2.14.1-0ubuntu3
Architecture: i386
CasperVersion: 1.340
CurrentDesktop: Unity
Date: Wed Jun 22 16:51:59 2016
ExecutablePath: /usr/bin/gnome-disks
LiveMediaBuild: Ubuntu 14.04 LTS "Trusty Tahr" - Release i386 (20140417)
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gnome-disk-utility
UpgradeStatus: No upgrade log present (probably fresh install)