Why do I get the error "... version `Qt_5.8' not found ..." when trying to run "4k Video Downloader"?

Summary

1. I've just installed the 32-bit version of the "4k Video Downloader" package
into /opt/4kvideodownloader/

using the instructions at

https://www.click4infos.com/install-...eo-downloader/

The main steps that I followed on that webpage are 4 and 8. As instructed, I
have put the downloaded and unzipped directories and files in

/opt/4kvideodownloader/

2. a) But when I run 4kvideodownloader, I get the following error:

Code:$ /opt/4kvideodownloader/4kvideodownloader-bin
/opt/4kvideodownloader/4kvideodownloader-bin:
/usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not found
(required by /opt/4kvideodownloader/4kvideodownloader-bin)
/opt/4kvideodownloader/4kvideodownloader-bin:
/usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not found
(required by /opt/4kvideodownloader/libQt5Script.so.5)
/opt/4kvideodownloader/4kvideodownloader-bin:
/usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not found
(required by /opt/4kvideodownloader/libQt5Widgets.so.5)
/opt/4kvideodownloader/4kvideodownloader-bin:
/usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not found
(required by /opt/4kvideodownloader/libQt5Xml.so.5)
$b) Also, "$ konsole" will no longer launch from a terminal, but gives similar
output to the above ("a)"). See Full Details "6.".

3. I wondered if doing step "8" of the "www.click4infos.com" instructions at "1."
above has caused the problem. Step 8 says

Quote:

Add the program libraries to the system; $ sudo ldconfig /opt/4kvideodownloader/

4. My Question:

I'm out of my depth with this, so could you tell me what is wrong, and what I
need to do to make 4kvideodownloader run OK (and make "konsole" launch as it
did before)?

Full Details

5. I downloaded the 32-bit 4kvideodownloader from

https://downloads2.4kdownload.com/ap...3_i386.tar.bz2

6. Launching "konsole" from a terminal worked fine before installing
4kvideodownloader. But now, I get an error similar to the one that occurs when
running 4kvideodownloader, as follows:

Code:$ konsole
konsole: /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not
found (required by /opt/4kvideodownloader/libQt5Widgets.so.5)
konsole: /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not
found (required by /opt/4kvideodownloader/libQt5DBus.so.5)
konsole: /usr/lib/i386-linux-gnu/sse2/libQt5Core.so.5: version `Qt_5.8' not
found (required by /opt/4kvideodownloader/libQt5Xml.so.5)
$7. I'm wondering if the error at "2.a)" in the Summary, namely "version `Qt_5.8'
not found" is a red herring. This is because I THOUGHT I'd seen a library name
relating to 4kvideodownloader of something like libQt5Core.so.5.6 somewhere on
my filesystem. I believe that the appended ".6" is the so-called "minor number".

So wouldn't this suggest that the libraries supplied with the 4kvideodownloader
installation are Qt version 5.6 (ie correct), and not 5.8?

8. /opt/4kvideodownloader/ contains

Code:$ ls -1 --indicator-style=slash --group-directories-first /opt/4kvideodownloader

audio/
doc/
imageformats/
platforminputcontexts/
platforms/
translation/
xcbglintegrations/
4kvideodownloader-bin
4kvideodownloader.sh
libavcodec.so.56
libavformat.so.56
libavutil.so.54
libcrypto.so.1.0.0
libicudata.so.52
libicui18n.so.52
libicuuc.so.52
libmp3lame.so.0
libportaudio.so.2
libQt5Concurrent.so.5
libQt5Core.so.5
libQt5DBus.so.5
libQt5Gui.so.5
libQt5Script.so.5
libQt5ScriptTools.so.5
libQt5Widgets.so.5
libQt5XcbQpa.so.5
libQt5Xml.so.5
libssl.so.1.0.0
libswresample.so.1
libswscale.so.3
libx264.so.148
$9. The config files related to "ldconfig" are as follows:

Code:$ ls -1 --indicator-style=slash --group-directories-first /etc/ld.so.conf*

/etc/ld.so.conf

/etc/ld.so.conf.d:
atlas.conf
fakeroot-i386-linux-gnu.conf
i386-linux-gnu.conf
libc.conf
zz_amd64-biarch-compat.conf
zz_x32-biarch-compat.conf
$All the above files (in this entry "9.") have old modification dates, so it
appears that they have not been modified/created as a result of running
ldconfig.

10. A website says that the following tells me what my VERSION of Qt is:

Code:$ qmake --version
QMake version 2.01a
Using Qt version 4.8.7 in /usr/lib/i386-linux-gnu
$