@libreoffice last available _portable_ version, but that was only visible in the thread context. 24.2.3.2.
The problem occurs after selecting an *.oxt files (tried different ones) and selecting "Only for me". No installation and this error appears: "an error occurred during file opening at C:/cygwin64/home/buildslave/source/libo-core/ucbhelper/source/provider/simpleioerrorrequest.cxx:35" in an "Extensions" error dialog.