In Writer, DocX files won't open, after unsuccessful attempt to upgrade to most recent version

I have Version 24.8.6.2 (X86_64) of LibreOffice Writer (using Windows 10, 64 bit). After trying unsuccessfully to update to Version 25.2.4, the most recent version of LibreOffice Writer, I was (and still am) unable to open some of my Writer documents. I always save my documents as DocX files in the “Word 2010-365” format. I tried resetting the default format setting, but that did not help. After multiple tries of not being able to open documents, I installed the paid edition of LibreOffice, but that only partially solved the problem. Now, the documents will sometimes open and sometimes not open. and, to make matters worse, I was unable to complete the update to version 25.2.4.
What do I have to do to be able to open all of my docx documents? If I have to uninstall and reinstall libreoffice again, will I lose any of my documents?

No, nothing is lost as a result.

Maybe your antivirus doesn’t recognise the new version of LibreOffice.

Try adding LibreOffice (soffice.bin) to its allowed list

From where did you download that edition? And how much did you pay?

Lets hope @Imperfect1 meant the App Store of his OS linked from here:
https://www.libreoffice.org/download/libreoffice-from-microsoft-and-mac-app-stores/