Arch Linux

I have opened "mkvtoolnix-gui" now and I receive an error (see attachment):
"A problem has been detected with this installation of MKVToolNix:
The versions of mkvmerge (51.0.0) and the GUI (1..) differ.
Certain functions won't work correctly in this situation. Please re-install MKVToolNix or fix the problem manually."

$ mkvtoolnix-gui --version
mkvtoolnix-gui v51.0.0 ('I Wish') 64-bit

$ mkvmerge --version
mkvmerge v51.0.0 ('I Wish') 64-bit
------------------------------------
Output of menu option "Help" > "System Information":

# MKVToolNix

## General

* MKVToolNix GUI version: 1..
* mkvmerge version: 51.0.0
* Installation path: /usr/bin
* INI file location: /home/juan/.config/bunkus.org/mkvtoolnix-gui/mkvtoolnix-gui.ini

## Installation problems

* Type: MkvmergeVersionDiffers, info: 51.0.0

# System

## Operating system
* Name: arch
* Version: unknown
* Pretty name: Arch Linux

## Screens

### Screen 0

* Device pixel ratio: 1
* Logical DPI: 96.0473x96.0473
* Physical DPI: 108.918x108.918
* Physical size: 597x336
* Virtual size: 2560x1440
* Geometry: 2560x1440@0x0

# Qt

* Version: 5.15.1
* Build ABI: x86_64-little_endian-lp64
* Compiler: g++ 10.2.0

## Environment variables

* `QT_AUTO_SCREEN_SCALE_FACTOR=0`
* `QT_SCALE_FACTOR=`
* `QT_SCREEN_SCALE_FACTORS=`
* `QT_DEVICE_PIXEL_RATIO=`