When I opened the Software centre, I could not see any application. I am getting an error when I try to reinstall it
Solution 1:
Explore with ps -fp8394. If process 8394 exists, you (or unattended-updates) are updating the packaging system elsewhere.
If process 8394 does not exist, the lock file may be left over from an update interrupted by a sudden reboot. If so, it should be deleted, BUT your packaging system may be in an inconsistent state.
Do
sudo apt update
sudo apt upgrade
and Read the Error Messages.
An alternative explanation for ps -fp8394 being empty may be that process 8394 has finished, and deleted the lock file.