Conflict with the Update Manager in Ubuntu

During a process of installation / update of software, it happens sometimes that a conflict is created between the operating system and the software itself.
The error message, to which we will find the solution, is below.

Only one software management tool is allowed to run at the same time.
Please close the other application (eg <<Update Manager>>, <<aptitude>>, or <<synaptic>>) first.

This error message indicates that is already running a process of updating and then you can not run another, as they probably would come in conflict between each other.

While surfing the web, I found several possible solutions, so deciding to put all of them together in a single post.

Step 1: terminate the process that creates the conflict

On the official forum of Ubuntu, I found a couple of excellent advice, which we are going immediately to analyse for first.

Open the terminal and type:

ps aux > ActiveProcesses

to save all the active processes in a file named "ActiveProcesses"
Through one of the following commands, always from the terminal, you can go then review the file saved, looking for any instance of processes synaptic, dpkg, apt-get or gdebi.

gedit ActiveProcesses 
less ActiveProcesses

If you fine one or more instances of them, just end them one at a time, replacing the following command parameter process_number with the number of the process concerned (can be found next to the user name to whom belongs the trial).

kill process_number

For example, if you find the following lines:

myuser 4512 2.5 1.4 35876 11400? S 21:40 0:00 gksu /usr/sbin/synaptic 
root 4513 9.4 4.2 57616 32608? Ss 21:40 0:03 /usr/sbin/synaptic

Is necessary needed that you enter that the following commands:

kill 4512; kill 4513

After finishing all the processes that create conflict, try installing anew the software in question. If it would be still the problem, go to Step 2.

Step 2: Delete the lock file

When a management tool software runs, tries to create a lock in /var/lib/dpkg/lock to avoid the possibility of conflicts with other instruments. If the attempt to lock fails, it means that another process has already locked the file and then was forced to quit generating an error.
The command lsof (list open files) can help you to control what process is using the file, preventing de facto the other management software tools to open it.

sudo lsof | grep/var/lib/dpkg/lock 
synaptic 7453 root 7uW REG 3.3 0 2246464/var/lib/dpkg/lock

As in the previous method, just a kill process_number to terminate the process.

If you do not have been detected processes that use the file lock, try the direct removal of the file with the command:

sudo rm -f /var/lib/dpkg/lock

After trying for the umpteenth time installing the sofwtare, if it not still works, go to the next step.

Step 3: previous installation corrupt

As described in a article forum official Ubuntu Australia, Tried by the terminal following solution:

sudo dpkg - configure -a

This solution is useful if a previous installation was blocked or if dpkg has crashed while running.

Well, we reached the end of this mini-guide, any residual problem should be resolved (... at least for me was so!) And finally you can install your software (Skype, aMsn or any you want) so that has been so worrying for you!