When saving a worksheet update in Libreoffice Calc 5.2.3 for Ubuntu, I get a message stating: 'Installing fonts on request isn't supported'. This also happens when the worksheet is on autosave. Any ideas?

This happens all the time and only since the upgrade to 5.2.3.

Does the answer to this help: http://askubuntu.com/questions/832857/installing-fonts-on-request-isnt-supported-error-message