Encountered this issue while trying to run Open Office from a newly installed Ubuntu box:
This application could not be started.
User installation could not be completed.
To fix this issue you need to basically reset the config of LibreOffice. This can be done using the following command (Warning: This deletes all your settings and config wrt LibreOffice):
rm -rf ~/.config/libreoffice
Note: This issue can also occur when the permissions of the config folder is incorrect (root instead of user), use this command to fix that issue:
chown haas -r ~/.config/libreoffice