Unable to install Language Tool 4.3 in Win 10 version of Libreoffice 6.1.3.2 64 bit

I have upgraded to Java 8.19.1, 64 bit. When a try to install to Libreoffice, I get this error:
“Insert duplicate implementation name org.languagetool.openoffice.Main”. What does this error message mean, and what needs to be done to fix it?

Sounds like there’s an old version of the add-on still installed in LibreOffice. You could try whether this approach helps.

Here’s a more detailed answer: update error - English - Ask LibreOffice