Com's questions

I had to reinstall Ubuntu because of some graphics errors I couldn't handle(based on my research).

I made a Live USB and finished a complete installation. After loading and installing software updates, mouse and system works fine. Some minutes later everything freezes.

An example: I am looking for some apps in ubuntu center, watch files etc, click on settings and then I can't enter anything.

Similar when the mouse or touchpad don't work, but it is not the problem.

I tried 2 more times to install Ubuntu and it is always the same. I never faced that problem before.

I am asking here from my phone. Any help would be appreciated. Thank you!!

I have a strange problem. I installed Postman following the instructions from the Internet. Now it can be opened, works fine etc. but icon is not displayed. occupies a place, shows that it is open and it writes a name when it crosses over it but irritates me because it can not be seen. What is the problem and how can I fix it? I tried to reinstall it and same happened...

How to completely remove Notepad++ in Ubuntu 18.04 terminal?

I can't find it in Synaptic package manager, and don't know where is on system, but I can see an icon in Activity. It is probably not completely installed, because I can't open it.

I'm new with Ubuntu and Terminal, I have Ubuntu 18.04. First time I installed LAMP server using tasksel...and everything was working fine, and then, after some time, I can't start anything. I tried to use some commands but all i see is: can't restart because of error.

I remove all thinking it might help, and then it's all good. But i don't want to delete and install every time that server. Can somebody tell me what might be the problem and how to fix it?

If I use sudo apache2ctl restartthis happens:

(2)No such file or directory: AH02291: Cannot access directory 
'/var/log/apache2/' for main error log
(2)No such file or directory: AH02291: Cannot access directory 
'/var/log/apache2/' for error log of vhost defined at 
/etc/apache2/sites-enabled/000-default.conf:1
AH00014: Configuration check failed  
Action 'restart' failed.
The Apache error log may have more information.

EDIT: now everything's working except mysql service. I tried systemctl status mysql.service and this happened:

● mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor 
preset: enabled)
Active: failed (Result: exit-code) since Tue 2018-07-10 19:53:53 CEST; 
6s ago
Process: 6021 ExecStart=/usr/sbin/mysqld --daemonize --pid- 
file=/run/mysqld/mysqld.pid (code=exited
Process: 6012 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre 
(code=exited, status=0/SUCCESS)

Why I can't restart it or anything?? Please help