Description:
On a machine working with lubuntu 20.04 up to date

I have install libreoffice 24.2 from 
https://mirror.cyberbits.eu/tdf/libreoffice/stable/24.2.1/deb/x86_64/LibreOffice_24.2.1_Linux_x86-64_deb.tar.gz
install works correctly but when i try to launch libreoffice 

i have the message 
libreoffice24.2 icon theme not found. /opt/libreoffice24.2/program/soffice.bin: symbol lookup error: /opt/libreoffice24.2/program/libvclplug_qt5lo.so: undefined symbol: _znk7qwidget6screenev version qt_5 "elementary"

i have tried to uninstall libreoffice 
(sudo apt remove --purge libreoffice
sudo apt clean 
sudo apt autoremove) and to reinstall it (sudo dpkg -i LibreOffice_*/DEBS/*.deb in the Download folder after unpacking the download package) 

I have the same message 

i will try to go back to libreoffice 7.5 in order to work 

Steps to Reproduce:
On a lubuntu 20.04 up to date, download libreoffice deb packs via the libreoffice website
2.in a terminal, go to download folder, unpack the download, and use sudo dpkg -i LibreOffice_*/DEBS/*.deb to install - install seems to be OK. 
3. launch libreoffice24.2. the splash screen display furtively, then an error message appears


Actual Results:
Icon theme "elementary" not found.
/opt/libreoffice24.2/program/soffice.bin: symbol lookup error: /opt/libreoffice24.2/program/libvclplug_qt5lo.so: undefined symbol: _ZNK7QWidget6screenEv, version Qt_5

Expected Results:
libreoffice launch correctly


Reproducible: Always


User Profile Reset: Yes

Additional Info:
first try with libreoffice 7.5 installed. This one works correctly
then i try to uninstall all libreoffice and to reinstall libreoffice 24.2 the problem isn't solved. 

i have tried to desinstall all libreoffice,then adding 
http://ppa.launchpad.net/libreoffice/ppa/ubuntu
to my repos and to install again 24.2 
does not work, same error

I have reinstalled libreoffice via apt (7.6.5.2 60(Build:2)) this one works
but some new features on math existing on the 24.2 is better for me

going back to libreoffice 7.6