See above
PS: I can no longer sign in to my account because I am expected to do so by means of platforms that I don’t use.
Take a look to Tools -> Options -> LibreOffice -> Personalization and check whether another Preinstalled Theme fits your needs. Notice: Do not try to use Own Theme: Firefox Themes do not work any longer due to API changes at mozilla.org.
It is strange that you are having trouble signing in. What platform are you using? What platforms are you expected to use?
Thank you for the suggestion about resolving the problem, Opaque. Unfortunately, it didn’t work for me: there seemed to be no pre-installed themes available. I’ll just have to peer more closely at the screen!
However, I managed to sign in to my account this time, using my usual ID & password: I’ve no idea why they didn’t work before.
Ok - then you obviously use a previous version of LibreOffice. My version is:
Version: 6.2.3.2
Build-ID: aecc05fe267cc68dde00352a451aa867b3b546ac
CPU-Threads: 8; BS: Linux 4.12; UI-Render: Standard; VCL: kde5;
Gebietsschema: de-DE (de_DE.UTF-8); UI-Sprache: de-DE
Calc: threaded
Thanks again, Opaque. I am using the latest version that is recommended for “conservative” users, whereas you must be using the one for the “technology enthusiast, early adopter or power user”. I definitely don’t fit into the later category! I’ll just have to live with my version until the next release comes along. Thanks for taking the trouble to respond.