Pop up states:
Cannot obtain lock E: Could not get lock/var/lib/dpkg/lock-frontend.
It is held by process 2197 (unattended-upgr)
W: Be aware that removing the lock file is not a solution and may break your system.
E: Unable to aquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), is another process using it?"
What should I do? I do not know if another process is using it!