Softwares open but won't work

Some days ago I start to experience this:


What you see in the picture is the “splash” screen of gnome, just for show the problem.
Basically, a lot of softwares I have installed on my pc seem to open but won’t work, opening some empty stuff as the picture shows.
Any solution?
Thanks in advance.

I’m not quite sure what I’m lookin at as I’m not using gnome myself, but whenever software doesn’t seem to start, in my case, I try to launch it from terminal.
In terminal there may then appear error messages that might indicate what is going on.

Tried, but nothing happens, neither they open if I write the name of the choosen software. For instance, if I try to open Gimp from terminal, simply it returns “gimp: command not found”, even for other softwares…

You probably don’t even have gimp installed.

What is the output of:

$ pacman -Qs gimp

And also:

$ echo $PATH

Sorry, I did a mistake. I installed it with flatpak, that’s why it says “command not found”.
Anyway, also if I try to open it with ’ flatpak run org.gimp.GIMP ', it return some “critical” and the problem remains.
For others softwares installed with pacman is the same. Something regarding graphic libraries I guess, for what I can read from the terminal…

[user@hostname ~]$ flatpak run org.gimp.GIMP

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.588: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55468800' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.588: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb554967e0' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.592: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55513620' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb5550cf80' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55500920' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55506090' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb554b6b00' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb555050d0' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55484410' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55512b10' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55510190' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb5550df20' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55500a20' of type 'IBusInputContext'

(gimp-2.10:2): GLib-GObject-CRITICAL **: 11:13:56.595: ../gobject/gsignal.c:2626: signal 'require-surrounding-text' is invalid for instance '0x5beb55501fb0' of type 'IBusInputContext'

In the case of Kate, terminal doesn’t return absolutely anything like everything is good, but anything appear on the screen, but there is an instance for it…