I just spotted that HTML editor is not available at my local Limesurvey installation, which I do not use very frequently. It is OK at my online hosted version. Both are 1.90+ Build 9642.
I found this discussion then and checked config-defaults.php In both files is $sFCKEditorURL = "$homeurl/scripts/fckeditor.266"; as well as in freshly downloaded file from LimeSurvey download site.
I tried all possible variants of changes of $sFCKEditorURL at the local installation but html editor did not show up.
Any idea why editor is OK online and not OK at local with the same config-defaults file and why it did not appear after I made changes suggested in this discussion earlier?