Performing Step 5 of the Package Manager Troubleshooting Procedure is almost always sufficient to solve this problem, as well as many other package management problems. (Or as tijybba commented, rebooting often works.)
Open a Terminal window (Ctrl+Alt+T an run these commands:
sudo fuser -vvv /var/lib/dpkg/lock
cat /etc/lsb-release
uname -a
sudo rm /var/lib/apt/lists/lock
sudo cp -arf /var/lib/dpkg /var/lib/dpkg.backup
sudo mv /var/lib/dpkg/status /var/lib/dpkg/status-bad
sudo cp /var/lib/dpkg/status-old /var/lib/dpkg/status
sudo mv /var/lib/dpkg/available /var/lib/dpkg/available-bad
sudo cp /var/lib/dpkg/available-old /var/lib/dpkg/available
sudo rm -rf /var/lib/dpkg/updates/*
sudo rm -rf /var/lib/apt/lists
sudo rm /var/cache/apt/*.bin
sudo mkdir /var/lib/apt/lists
sudo mkdir /var/lib/apt/lists/partial
LANG=C;sudo apt-get clean
LANG=C;sudo apt-get autoclean
LANG=C;sudo apt-get --purge autoremove
LANG=C;sudo apt-get update -o APT::Cache-Limit=25165824
sudo dpkg --configure -a
sudo dpkg --clear-avail
LANG=C;sudo apt-get -f install
LANG=C;sudo apt-get --fix-missing install
LANG=C;sudo apt-get update -o APT::Cache-Limit=25165824 && sudo apt-get dist-upgrade
Written by Contributors to the Ubuntu documentation wiki.
If that doesn't work, please add all the text from the Terminal to your question (by editing your question). This will provide valuable information for working further on your problem. But it will probably work.