I’ve encountered this problem several times before:
LibreOffice, once started, doesn’t appear to be running in any way (interface doesn’t pop up, no button in the windows taskbar), except when looking in Windows Task Manager, several LibreOffice processes seem to be running (some of which have the LibreOffice writer icon, and others (mostly more) with the (neutral) white sheet icon.
Hi
When this happens it is necessary either to reboot the computer, or to stop “manually” the processes that block the startup.
To do this in the Windows Task Manager (Process tab), select soffice.bin then click Stop Process (the dependent soffice.exe will be automatically stopped).
Regards
Under Win10 with recent versions of LibO I no longer got an soffice process. Instead a background process ‘LibreOffice’ appeared in addition to the application and its windows.