This may happen if 'Synaptic Package Manager' or 'Software Updater' is open. Some apt command is running in Terminal. Some apt process is running in background.
$ W$ }4 n8 @; N6 g+ U
For above wait for the process to complete. If this does not happen run in terminal: sudo killall apt apt-getIf none of the above works, remove the lock files. Run in terminal: (Note that this can seriously break your system.) sudo rm /var/lib/apt/lists/locksudo rm /var/cache/apt/archives/locksudo rm /var/lib/dpkg/lock*then reconfigure the packages. Run in terminal: sudo dpkg --configure -aand sudo apt updateThat should do the job. |