Bdtyktl

My Ubuntu OS' version is 18.04.1 LTS.

When I start gedit, this is the result gedit screenshot:

Same problem arises with GNOME Calculator:

I think some things wrong with GNOME programs. I wish to know followings:

• Why is this happening?
  
  


• How can i fix this?

By the way - your calculator may be a 'snap' program.

Try: sudo snap install gnome-calculator

Try: sudo snap refresh

Install the 'Synaptic Package Manager' and search for gedit,

using:

sudo apt-get update 

sudo apt-get install synaptic

This will help to figure out what is going on with any program/package issues.

You could experience a problem related to input method modules.
(https://bugs.launchpad.net/ubuntu/+source/gtk+3.0/+bug/1760818)

Try starting e.g. gedit by disabling GTK_IM_MODULE

GTK_IM_MODULE=none gedit

and check whether the issue is gone.

If it is gone, you could try to set GTK_IM_MODULE to none by invoking

im-config

and selecting choice "none" in the dialogs.

A reboot is necessary, afterwards.

This link may be of help:

gedit not working? [duplicate]

Using: apt-get install --reinstall gedit must have space before the --reinstall

or:

sudo apt-get purge gedit && sudo apt-get install gedit

Also try:

sudo apt-get purge gedit gedit-common

sudo apt-get clean

sudo apt-get install gedit

And do it for the Gnome calculator:

sudo snap remove gnome-calculator

and enter the following to install the deb version:

sudo apt install gnome-calculator

Another possibly is to update the 18.04.1 OS system with:

sudo dpkg --configure -a

sudo apt-get update

sudo apt-get upgrade -f