Faq/General/LibreOffice hangs its process on window close and I can't open another instance (Windows)/en

You are on Windows and using LibreOffice. If you open any document in LibreOffice, then close a window and can't open another document (you can see in Task Manager LibreOffice processes are still running) a possible cause is a problem with saving a backup of the user profile. At first, check folder permissions (LibreOffice profile folder - %appdata%\LibreOffice).

For more insights use Process Monitor utility: filter processes by soffice.bin and check the results - you can see what files LibreOffice is trying to access and what are the results.

If you are using LibreOffice in a Windows domain environment with folder redirection (maybe also with mobile profiles), another issue might be offline files. Make sure your user doesn't have any synchronisation conflicts and your computer has enough disk space for offline files.

As a reference you can also see this bug report