Just did a full reinstallation of Windows 7 and installed LibreOffice 220.127.116.11. Attempting to intall Language tool using LanguageTool-3.2.oxt resulted in the Extension Manager freezing and the LO freezing, with a 'not responding' status. Stayed like that for a long time. Had to end it with Task Manager.
Thanks for your report. We never before had reports of this specific problem. Other than just trying again, you should make sure that you have Java 8 installed and that it's activated at
Tools -> Options -> Advanced in LibreOffice.
Thanks for your reply. I installed Java and there were still error messages, but then I found Language Tool already installed. So please consider this one closed.